Basically, if you're not getting sick...your house is likely clean enough already.

I agree. Go for 70% plus or minus 10% that's how nature functions. I rarely get sick and I'm not the tidiest person. Clean, but not tidy. Wash hands often with any ol' soap. Close the lid, put the tooth brush under cover.

There have been some studies done that show a close relationship with the high number of allergies and resperatory issues with kids and the absolute cleanliness. A little dirt is good they're finding. Scrub out scuffs and nicks and put on a bandage, followed by a Boo-Boo kiss of course, and they're back out the door!