@lookitmychicken One day I'll stop being thrown by the fact "friendship bracelet" can mean two extremely different kinds of craft, but that day is not today x')
For the bottle lids I've heard that it's so you can't throw the bottle at the performers in a way that could hurt (without the lid it'll empty itself while flying and land harmlessly), but I have no clue if that's the true reason or just an urban legend =')