Is there a quick cure for refrigerator drip tray stink?
If it's a recurrent problem, I'd go with Copper sulfate over bleach.
The stuff is used as a herbicide, fungicide and pesticide, and 25 grams or so dissolved should render the tray lifeless. You can get copper sulfate at greenhouse supply stores and some hardware stores. If you can't find CuSO4-6H20, Bordeaux mixture should work as well.

Bleach and its breakdown products are strong oxidizers, and will corrode your metal tray.
Copper sulfate isn't an oxidizer, and won't do that.