Try crumbled up newspapers and leave them in your dehydrator for a few days (not turned on of course). This works for getting nasty smells out of old fridges, so it might work for a dehyrdrator.

Wash it with baking soda water, and then maybe leave some loose baking soda on the mat for a few days or with it turned on. It absorbs odors and it is safer than febreeze!

Also, lemons. MM.. I have roommates and my fridge gets disgusting often. Baking soda and/or spent lemons used to scrub it out gets rid of scent/s.

Good luck.

I second the newspapers idea. I was going to post that. This works with a lot of things, like smelly shoes.