I have 40mm plumbing waste pipe slid over my 38mm battens, as chafe protection (sure, it taps against the mast, but this tells me that the sail needs sheeting in). The forward end is secured by the screw that holds the sail to the batten, and the after end is far enough aft that it acts to stop the semi-short batten parrel from sliding forwards.

I cannot think of a way of shielding a hose clamp sufficiently well to use it on a long distance cruising sail, though it might be OK on a sail used only for a few hours of sailing each week, if taped over.

I've used a screwed-on plastic knob successfully for many thousands of miles, though. One small hole for a self-tapping screw is unlikely to cause damage, unless the batten is under-sized.

Hose clamps. Do not make a hole in an aluminum tube!

I have found a good method on my sail with the idea actually coming from David Tyler. It is a pair of studs made in my case from a round of 12mm thick plastic (formed by a 12mm diameter hole saw), fastened to the batten with a stainless steel screw and the parrel is lashed around the batten behind the studs. Look in my member profile photo albums - New Sail Details, and you will find a photo. I have them on both the alloy and carbon tube batten and the method has proven reliable and trouble free, never slipped, never pulled out of the batten, and done no damage to the sail.