Hey! Sorry I didn't see or respond to this post earlier... I've definitely apple garded most of my
Coach purses (the non-patent leather varieties, anyway) and have yet to experience any bad side effects with the rain garde. I've sprayed my gunmetal crackle-leather maggie, black metallic claire, and textured leather audrey, all with no bad side-effects. I've ALSO sprayed my pink exotic embossed madison carry-all-- it took a while to dry, longer than the other bags, but once it was dry, it looked exactly the same. All are still looking good!
Just FYI, sometimes it takes a while for a good dose of garde to set. I generally let a bag sit overnight, or at least for 30 minutes if I'm waiting to spray the other side of the bag. The embossed exotic madison leather, I had to wait about 10 hours for it to dry (but turned out great). The crackle leather took around 1-2 hours.
I've never experienced any bad side-effects of accidentally spraying the metal-- just wipe it off, and it's fine.
The only bad thing that's ever happened to one of my bags as a result of apple was actually with the conditioner. Do NOT use the apple conditioner on regular white Madison leather... it turned the edges of my gray/white leather Spectator shoulder bag a HIDEOUS flourescent yellow. Just so you know!