Beastie Band Care?

I hope this is an okay place to put it. If it needs to be moved to another, feel free!

Marlee wears a Beastie Band. Every once in while I take it off long enought to massage her little neck so her hair doesn't get permanently messed up (and she loves it), and to clean it. As of now all I do is trim any strings hanging off and use a lint brush/sticky thing to get off her shed hair. Is there anythign else I need to do, like wash with soap and water or anything? I do have a 2nd Beastie Band, but want to make sure she'll full grown before using it on her.

This is technically another topic, but....how long til a cat is fully grown? Marlee is somewhere around 8 months. I keep thinking she'll grow a little more cause she seems sorta small. I mean she weight 9 lbs but still looks little. Could she be done growing arleady?

I use safety collars, but I do the same thing to care for them. Have never washed them.

I think that 18 months - 2 years is when a cat is fully grown, pretty sure I heard that some breeds grow until 4 but don't quote me on that lol. I have 5 10 month old kittens who all weigh around 10 pounds, but their bodies are much smaller than my 2 year olds and he is only a few pounds heavier.

If Zissou's collar gets dirty when we're on a walk or something, I just put it around my wrist while I take a shower and make sure to rinse it really well. When it's dry I put it back on. Don't put it in the dryer!!
I don't think you need to wash it unless its dirty though. I do if it gets that orange puffball stuff on it (but then, she gets a bath too with that stuff) or mud or once, ketchup (accident!).

I don't know anything about Beastie Bands, but I can answer the growth question...

Cats grow until about two years of age. Sometimes they grow a little after two years, but most are full grown by a year and a half.