Virtually every anti-bacterial cleaning product that I buy claims to that it will kill 99.9% of bugs. So my questions is - what type of bacteria or viruses are the 0.1% that these products can't kill? They really must be the sort of thing that you wouldn't want to meet down a dark alley.

If skin cleansers are used to strip the grease and oils from our skin, does that leave the pores wide open, so that dirt (or other face creams) can get in and block them?

I have also read (on here) that our natural skin oils slows bacterial growth, so cleaning would let the bacteria breed more readily?