Hmmm, interesting. I've used Listerine in a lot of ways but never on rainrot. Good idea. We had a gelding, when I was a kid, who was very prone to pick up rainrot. We used a topical funguside from Jeffers and it did really well. Later, when I was paying the bills and couldn't afford to order the stuff, we used baby oil on them. We'd put the baby oil on one day and then the next day, we'd work at the lesions gently and then repeat the process until we had a clean coat. I can see how using listerine would be more effective because of it's antiseptic properties. Glad I read this thread. Thanks.