Hey Jessica...
Right now, Peanuts tail hairs fell out due to him being sick. Now instead of the NICE top of the tail he had, its all spiky and icky looking. I can't say either of my boys make a mess of their tails, but I had an old show mare who did, and her tail was WHITE!
Needless to say, I try and wash my boys tails at least every 2 weeks. Then I braid them and for Peanuts, I roll it up in the braid so that its just above his hocks, and then I band it in that roll. Dealer just gets a braid, and he is fine about it.
We never actually did anything about the mare. I simply had to show her with a yellow tail, although when I bathed her, I would take extra care to get out all the poop.
As for Chantilly rubbing the top of her tail, I suggest a trip to Ozard! I got a nylon stable sheet and I must say, its AWESOME. The tail cover on that thing works SOOOOOO well. It covers the tail just to the point where a horse cannot rub it. Plus I haven't seen either of my boys get it off, and they are MASTERS of getting naked. It was only like $36, and trust me, I know how hard it is to buy tack when paying for show fees and such.