I scrub mine with a brush and bleach after every hatch..I could care less about looks only hatches
then when weather permits I sun it for several hours..100 degree sun baking will kill about anything.When I turn it back on I crack the lid for a bit and let the smell which is very minimal out and also some of the excess humidity from the water it may have absorbed...but no the bleach won't hurt the eggs.I get near 100% hatch rates on every bunch.Make sure you clean the lid as well..it can hide nasty no see-ums that will make for some bad hatch rates-don't forget under the fan!