Listerine does not kill mites. The best thing to treat fur mites is ivermectin. If you take your rabbit to the vet they will give the rabbit a shot. Generally they are gone with one shot but they usually give them another at the 10 day mark. If you have an entire herd to treat the vet can show you how to treat the mites at home with the ivermectin. Ivermectin can be a dangerous drug if the incorrect amount is given. Unless you have experience with dosing medication and understand the effects I suggest that you do not use this at home without consulting a vet first. Indeed you can buy ivermectin at most farm stores and a lot of rabbit owners treat their own. Keep in mind that most of these people although they claim to love their animals still consider them expendable.