My old Argentinian leather goucho hat isn't repelling water like it used to. It holds it off for a bit before it eventually soaks into the leather leaving a mark - until it thoroughly dries out. I've bought some Nikwax Waterproofing Wax Cream after looking through this forum. Can't find any real advice on application though. Wondering if I simply rub it in, or if I need to heat the hat first. Any advice would be greatly appreciated as I don't want to ruin this hat - I bought it in a one horse town in the Andes and carries so much sentimentality. Thanks Guys Owen.