How Do You Get Water Stains Out Of Uggs?

I don’t have real UGGs but I do have some Airwalk boots with UGGly water stains on them. When I bought them in the beginning of the winter, I sprayed them with water proofing spray to be sure they would stay their perfect chestnut color all season. Unfortunately, the ice and snow got the best of them and their chestnut perfection is no more. The ugly gray spots are annoying me. Is there any way to get rid of them?