Canava- Diluted bleach is perfectly fine for rats, if you have some sort of water system to go along with your rack it helps keep clogging down.

I use a cap full of Vanilla ( which is about a teaspoon if that) per water bottle. When i used it for my 9 mice it didn't have any smell at all coming from their tank, but i didn't use it for my two moms with their pinks( As a just in case thing) and all the smell was coming from their tank.