From my experience I reckon there are two good ways of getting junk rig promoted: articles in the mainstream yachting press and junkets.
I wrote three articles for Boating NZ, which, if I can judge from the response, were read by every boatie in the country. However, NZ is not a large country, so that's not quite so impressive as it sounds, although I've had a lot of people ask questions and compliment me on the boat.
Junkets certainly attract a lot of attention from nearby yachties. An early and successful one was at Brest in the 90s. Can't remember which year, I'm afraid: I'm getting old. The committee gave us pride of place as Vieux Gréements, which is an accurate description of junk rig, and we sailed in company with lots of luggers and gaffers.
The major problem, I'm sorry to say, is the complete lethargy of the vast majority of the membership, who rarely even have the courtesy to reply to personal emails inviting them to participate in a junket. Daniel put a huge amount of effort into his Rolling Junket, but elicited very little response from the many members in the USA. I have by no means given up trying, but one look at the Join In forum where junkets are mentioned, will show you how little feedback we get. General postings on the fora will usually be responded to by the score or so of members who regularly post. A personal email or letter (and no doubt a phone call, but this is probably too expensive an option) is slightly more successful. I'm not sure whether people will more readily plan 3 weeks ahead, 3 months ahead or 3 years ahead.
I hope you do try to plan a Baltic junket, Georg, and I hope you get an enthusiastic response. If you want any help at all in organising it, just ask me. I'll do anything that's possible from half way round the world. What a grand sight it would be: 44 junks strutting their stuff on the Baltic Sea! I wish you the very best of luck with the idea.