Anyone been to Tropical Islands yet? According to their rules, they make no mention of thongs, which doesn't surprise me. All they say is that nudism is not allowed while swimming, but in the saunas, you have to go naked.
You can go naked in any park in Germany, so thongs should not be a problem.
Please cutback on starting new threads and try to post messages as a reply to existing threads.
If you want to cut and paste from your word processor do not do it directly. First paste it into notepad or other basic ascii editor so that the formatting codes are removed, then cut again. This will give you clean posts.