This is a logical explanation, Arne. Using David's method of measuring the alcohol content, it would be interesting to try testing the fuel now and then for it's alcohol content.I have a feeling the alcohol will evapourate faster than the water, but it would be fun to test that. Certainly a wee dram (or fine Norwegian akvavit!) is best sampled shortly after pouring, whether diluted or not...

Oh the fun I'm going to have with my new stove :)  

Frankly, I don’t buy that explanation. ‘Cleaning alcohol’ is probably just some alcohol-water mix. Alcohol and water will not split in a tank (unlike milk and cream in un-treated milk).
I can only think of two ways that the alcohol in the canister gets weaker over time.

• 1.      The (unpadded) canister of alcohol attracts moist from the air, which dilutes it.
• 2.      The (unpadded) canister lets alcohol evaporate. If the alcohol is more volatile than the water, the water may not evaporate as fast, and then the alcohol contents will drop.

In any case, I think this is most likely to happen if the stove is sitting idle for some time between use.
My armchair, amateur guess is that this (diluting) process, suggested in case #1 or #2, will happen just as well with the pure 96% alcohol.

Still, I will keep this note in mind. Next time one of my burners run empty, I will dry the canister over low heat before filling it. I will also weigh the canister on my digital scales before and after the drying process.
Too bad I have no ways of actually measuring the strength of the alcohol.

Btw...
The reason why I think that the 80% alcohol is better on the Origo, is that this burner has limitations on the air-fuel mix. At full power there is simply not enough oxygen around to keep the flame blue (=full combustion). This means that some of the alcohol is only half-burnt, and the un-burnt part is soot. By reducing the strength of spirit to 80%, there will be fewer alcohol molecules searching for oxygen to react with, so this is like reducing the power setting. Maybe that would be just as good  -  reduce the power setting a little. This automatically leads to a leaner, and thus cleaner burn of the Origo, just because of the way that burner has been built.

Arne

PS: I can imagine that Annie Hill does not have problems with the burners getting weaker, since she uses her stove all the time

Compass24 never responded to our emails about the fire onboard from their shoddy Origo3000 copy last year, but they obviously took on our feedback and the product description (this is not small-print, it's the main info!) now makes it quite clear that it is unsuitable inside or on a boat, and a fire is your fault for not following the instructions to the letter:

Please observe the following instructions when operating the spirit cooker: -Don't operate the alcohol cooker unattended and never in closed rooms. -Make sure that the cooker cannot tip over and is placed on a fireproof base. -Make sure that the cooker has enough space on all sides, as the cooking pot deflects the flame and heat to the side. -Make sure that the stainless steel springs under the burner pots are high enough so that the burner pot is flush with the lid. -Check your camping cooker before each use for visible damage or other defects that could lead to malfunction. -Children should only stay near the cooker during operation under supervision. -Have fire extinguishing materials ready. A fire blanket or small fire extinguisher is best suited for this purpose. -Read the operating instructions and make sure that you operate your cooker in accordance with the manufacturer's instructions.

The fuel I use now on my Origo is a yellow-coloured, denaturised alcohol (ethanol). It is probably much the same as the BnQ stuff that Mark Thomassen mention below. It holds 80% alcohol, and I buy it in one-litre bottles in a local hardware store. The bottles make it easy to fill the canisters of the Origo.

To fill a canister, I take it out in the cockpit and fill it there. Any spills can easily be washed away with water. With one litre filled on an empty canister, the cooker can be heeled much further than you would heel your boat during sailing, still without spilling any fuel, so as long as you fill the canister in the cockpit, and wipe off any spills, there is no way the Origo will have a crazy flame-up.

The 80% alcohol keeps most of the flame blue at a higher power-setting than when using the 96% stuff. There is also less soot on the kettle. I have tested the time to boil 0.5l of water, and to my surprise, the 80% alcohol is just as fast as the 96% version.

The greatest long-term advantage with the Origo is to me that there are no critical parts which need maintenance. Simple as a hammer.

Arne

PS:
The only ‘technical’ issue is how to open the cooker to get at the canisters.
There is a little catch in the middle of the front of the stove, which must be pushed in to release the top half. In addition, both burners must be set to zero to free the lid. This you will do not only to fill the canisters, but also to fit or remove the rubber pads on top of the canisters. These pads are used if some time goes between use (days).
It will soon become second nature to do this.

I love my Origo.  I don't notice any smell from the spirit and I did notice it when preheating a paraffin cooker.  It's not as hot as gas and definitely not as hot as kero.

My main reason for not having a Taylor's stove on FanShi is that I got tired of everything smelling of paraffin.  There is also the drawabck that the deckhead discolours, even if you don't have flare-ups (and no regulated galley should have flare-ups).  As a hob, I would say that Taylor's is probably the best to cook on, because of the wonderful cast-iron hot plate. 

On the other hand, the Origo is the original plug and play cooker, which makes it very easy to remove and clean.  The fuel isn't that expensive, bearing in mind that you dilute it with water(!) and is easy to get hold of in most places.  My cooker doesn't get direct sunlight on it,  but I can imagine the flame could be invisible in bright sunlight. 

Unless you are marina based and own a car, propane makes no sense at all.  As well as the safety issues, refilling the bottles would be a nightmare.

I find it literally incredible that we are in the 21st century, in the middle of a climate crisis and that it is almost impossible to buy cookers that don''t require fossil fuels.