You can erase traces of you, where you've been. and replace it with a masking of dna. I can see how that might be reasonable under extreme circumstance in an area that you do not want your DNA to be found... but you;re going to leave 50+ other s behind? outside of erasing that you've been there, doesn't everyone else's DNA do that for you in public spaces? What is the realistic use of this? A bleach spray is not going to erase your hair and skin flakes. It may corrupt them if it is strong enough. This feels like someone selling an idea to the paranoid with little real world benefit.