It sat out, it wasn't in the warmest spot in the fridge, it smelled funky, and it's going to slowly cook for 10 hours????????
I'm sure others have told you that it's probably something you should have tossed. Slow cooking chicken isn't what I'd call a great idea, either, especially when it's suspect. You've got that famous 2 hour window to be below the 140 range. Slow cooking, especially 10 hours could leave you way outside that range. Once you get above that, do you really want to eat something that's been heating/holding for that long, considered how it smelled?
By this time, you've probably eaten it already. Personally, I don't think that would have been wise.