I have tried all the above even the cow poo where the cows are at. My feet seem to get too hot in rubber boots and the scent I think tries to come out the top too much and the rubber does seem to keep a unnatural scent to it. As far as the leather boots go I have used scentkiller on the many times and it does work o.k. but scentkiller is made for human odor not dirty musty leather. WhatI have found works the best is boot scent eliminator it comes in a spray bottle like scentkiller and it does work very well.