I don't want to sit on a toilet that big Harvey just sat on, but the maid didn't clean because it "looked" clean.
I don't get this logic... do you worry over sitting on a public restroom toilet after a hundred Harveys or Harriets - if it looks pretty clean? I mean, you can use a tissue seat covering but you're not washing out the bowl beforehand. Or are you?
If you've been fine after using public restrooms all these years, why not
relax about using a clean-looking hotel room toilet?

DisFlan is so right... this is more an emotional issue, not clinical/logical.
We also put our toothbrushes in the safe when we leave the room.

Oh my goodness, you poor dear, what is this about?!??
you have the best view in town over looking the city you're in but if there's blood stain you'll remember the stain...
It's reasonable to "look before you leap" - I think most people do that.
Avoid touching whatever doesn't look clean.
Have housekeeping rectify an observed cleanliness problem.
Wash hands with
soap, friction & running water after using the bathroom and before eating.
Use a paper towel to turn off spigots & open the exit door(s) when possible.
If someone has a depressed immune system (infants, elderly, sickly, etc.), it warrants special care. But we're healthy so this RN of 22 years does
not give this stuff more thought than the basic precautions above.
Remember that today's media is profit-driven. They really bombard us with every awful thing that can and does happen to a minority of people around the world while
ignoring the majority of people who are not suffering these ills for most of their entire lives. The media fuels our fears and makes us edgy and leery. Vacations are for relaxing - and that helps build the immune system!

Millions of people travel and do NOT get ill from a hotel room or a bathroom - especially where it looks quite clean (most germs don't survive drying fully on a hard surface).