The below-described experience happened years ago, but I still bet it is the subconscious reason that I posted this op.
You know that little, raised, small counter at the checkout lines at supermarkets, drugstores, etc.? I had personally witnessed a customer piling a bunch of snot rags on there. I actually stepped out of line; complained about it; set my intended purchase aside; and walked out. The customer that had done this was freaking out as I walked out.
And those snot rags were piled on there for the cashier, other employees, and the half-dozen other customers still standing in line to see. To this day I wonder what happened after I left.
When I was teaching lit, a friend of mine was teaching biology at the same high school. As a class project, they collected germs from numerous surfaces. Guess where they found the most? On the water fountains! There were more there than in the toilets.
You should get Chinese habits. Generally for Chinese prevention is a habit. My missus goes loopy if I touch any handrail or pretty much any surface that others touch when we are out - then goes double loopy if I touch my face with my hands ! First thing we do when getting back to the house, before touching anything, is to wash hands. Outdoor shoes never touch our floors as we change to slippers at the door, and this is the same in any Chinese house. After a few years here I have all their habits in this regard.