Ya know what, I just thought of this. It's a trick I used for years when I had rental properties, it'd take smell out of ANYTHING.
I used it to destink whole apartments, especially smoker's apartments.
Ammonia.
I'd get a gallon, set it out in dishes, close the place up, come back in a week, and every smell was gone.
With your humi, if baking soda or bleach solution don't work, get a dish of ammonia and sit it in a big green garbage bag. Open the humi up and sit it in there, too. Tie it off and come back in a week or two.
I'd really, honestly be shocked if that didn't work.
Don't use lemon ammonia, just regular ammonia.
