OK, I'm on a casing binge before bird seasons start. Just spent quite a bit of time cleaning mud spots off the outside of a nice canvas/leather case and thought there must be a better way. Does anyone here have experience using aerosol Scotchguard or anything like it on the exterior of canvas cases? I'm thinking I can mask off the brass bits, spray the case lightly and then just wipe off the leather parts. Anybody see a downside to this?