Hello, microbiologists!
I was having this discussion with a friend and I thought I remembered reading a paper about how it wouldn't work, but I couldn't remember where I read it.
The question is this. Different types of bacteria tend not to colonize the same surface, right? Instead of constant hand-washing or re-applying alcohol-based gels, could you use a sort of...benign bacterial yogurt to encourage just the benign bacteria to live on your hands? Would that be an efficacious way to prevent colonization with whatever random bacteria one is likely to pick up? The hand gels work, and don't contribute to antibacterial resistance so far as we know, but tend to be drying. So after gelling them once, you could apply benign bacteria to keep other stuff from trying to colonize your hands...sort of a effectiveness extender.
Obviously this would only be for day-to-day hand-cleaning, you'd still need to follow standard precautions for times when sterility was needed. Could this work?