Elora, that's so awful! I agree - McDonalds has lots of money... sue their butts off!!!
In answer to your question, I start by diluting the bleach to a 10% solution. I spray it on and let it sit for 10 minutes or so. I blot up any excess liquid, then spray with Simple Green and blot that up. Then I spray with a non-toxic unscented soap solution and scrub the heck out of it with a little brush. I rinse with water until all the soap is gone, then I dry it with paper towel and then with my hair dryer. Then I use my steam cleaner and do two or three cleans with that. Then I stick my nose in there and make sure I can't smell any bleach. I let it all air out for a while, and then in she goes. I wouldn't have to do so much except that the stairs are really rocky and there are lots of little crevices, so I have to make sure it's all perfectly clean - especially now that she has pinworms! I don't think anything could survive that cleaning regimen though. :lol: Once her pinworms are gone, I won't be using bleach any more. I'll stick with the non-toxic soap and the steam cleaner.