'll second the Physan 20. It's rated safe for hospitals and food prep
areas and claims to work great on fungus and other creepy stuff. There's a

You can find a less expensive version at most pool chemical supply retailers.
It sells in gallon containers for about $20.

Even less expensive is Bleach. A gal costs .79$, and I use it as a spray at %1,
and it works fine.

Wilford Neptune