A reader writes:
I wash my hands after going to the bathroom. I do, honest! But... maybe if I've only had a wee, I might just sort of... splash them a bit.
I know I'm being disgusting. How disgusting am I being?
Washing your hands without soap has almost no impact on the amount of bacteria on your skin. The only reason to do it is if all you want to clean off your hands is something, like, I don't know, sand or poster paint or something, that plain water easily removes.
But if your hands are covered with, for instance, garden soil, you may be able to get them apparently clean with plain water, but plenty of bacteria from the soil will still be there.
(UPDATE: It seems that it's a bit more complicated than that. Some researchers have found that you actually can wash your hands effectively without soap! You need to rub your hands together "purposefully" for at least 20 seconds under running water, though.)
Holding, not to put too fine a point on it, your penis while you urinate, probably will make your hand (or hands; I'm making no assumptions about your technique or dimensions) significantly more bacteria-laden. And the bacteria you pick up there can be nasty ones. Coliform bacteria, including ones that can cause an unpleasant stomach upset at the very least, are all over normal human skin in the approximate area that boxer shorts cover. You can't get rid of the buggers completely without bathing in antiseptic and scrubbing yourself with a wire brush.
(This is why no amount of bathing will prevent your armpits getting smelly when you start sweating again. The smell is the metabolic products of bacteria that thrive in sweat, and those bacteria live in the pores of your skin and can't all be killed without killing, or physically removing, the skin as well.)
Washing your hands with ordinary soap does, fortunately, get rid of coliforms on the surface of the skin, which is where they'll be if you've just been handing your privates. The soap doesn't kill the bacteria, but it gets rid of the oil on the surface of the skin, and washes most of the surface bacteria away with it.
(Hand sanitiser is usually based on alcohol, which also cuts the oil on your skin and actually does kill bacteria quite effectively. Washing with soap gives you live bacteria going down the plughole; hand sanitiser without washing gives you dead bacteria still sitting on your skin.)
And yet, persons in a normal state of health who don't wash their hands at all after going to the toilet will, demonstrably, not cause themselves, and everyone else they touch, to constantly get gastroenteritis. This is because bacterial transfer and growth is a statistical sort of thing.
Harmful strains of bacteria, and viruses for that matter, only become a problem when they get into your body, and can multiply faster than your immune system can get rid of them.
Let's say you've got a normal immune system, and you go to the bathroom, wash your hands in a perfunctory manner with no soap, and later on decide to eat some chips or perform some other activity that transfers bacteria from your hands to the upper portion of your gut.
You'll probably be fine, just as you will probably also get away with driving while mildly-illegally drunk.
But doing this buys you quite a lot of tickets in the Pathogen-Disaster Lottery. If you get a big enough dose of bad enough germs into yourself, your immune system won't be able to react and shut them down before they've multiplied into too large a population to stop, and then you'll be in trouble.
Which, again to not be over-dramatic, probably won't be the kind of trouble that kills you. But may be the kind that initially makes you afraid that you will die, and later on makes you afraid that you won't.
(Going around covered with nasty microorganisms also makes you a significant hazard for people with lousy immune systems - the very young, the very old, and the otherwise infirm. You don't even need to touch them; every time you leave a germy handprint on some non-antimicrobial surface, it'll wait there for quite some time to give the microscopic gift that keeps on giving to someone else.)
Any kind of hand-washing with soap will reduce the number of tickets you buy in the lottery you don't want to win, and washing your hands thoroughly with soap makes the risk essentially zero. (To do it properly you're meant to take at least 20 seconds, which can seem a rather long time while you're staring at yourself in the bathroom mirror.)
It's not just bacteria from your own body you have to worry about, of course. There are also pets, and rubbish bins, and all of those surfaces you have to touch any time you leave the house, and other people, and of course also other people's sticky, shrieking, waste-encrusted offspring.
My partner, a while ago, got really horrible gastroenteritis, the kind that sees you in hospital being intravenously hydrated on more than one occasion. I managed to get through the experience without getting the bug myself, and I didn't wall myself up in the attic and only touch her with robotic waldoes to achieve this. You'd better believe I washed my hands often, though.
Ever since, I wash my hands properly whenever I come home, and whenever I've handled anything that could plausibly be well-loaded with bacteria and/or viruses. And I've not had any tummy bugs since - though I didn't get them frequently enough beforehand for this to have generated any statistically significant data.
You don't need to go completely Howard Hughes about all this, but you also don't need to work in a hospital for a greater than zero level of germ-consciousness to be worthwhile.
Note that unless you've got a bladder infection or something, urine itself is very close to sterile (not quite fully sterile, because even a healthy urethra can contribute a few bacteria to it). Nice and warm, too.
So if you just put a soap dish on top of the toilet, you could probably get the whole job done in one operation.
And then commenters will, I hope, correct at least the most obvious flaws in my answer.