Has anyone ever used Sole Guard on there horses before? My POA is now retired from the show ring and in her golden years I'd like too do some serious trail ridding before she gets too up there in age! She's 16 right now. Anyways, she has tough pony feet but I want to give her a little extra protection so I am considering using Sole Guard. Does it really last 3 weeks? Does it provide good protection? Is it hard to apply?