Indeed a very good topic to bring up!
Unless he is a lazy as as I am, and also uses Anti-septic soap to do the dishes because it’s cheaper when you need to bulk buy it anyway. 
Exactly.
To begin, I would repeat @Coma:
Sterilization becomes more necessary when something will be forcing it’s way against the flow of blood.
When you made your discovery about the meatyness of us, I bet you had to fight off the blood spilling out of yourself first, right?
That flow of blood also helps you get rid of the external bodies. so when you toss in your bandaid, even if it is not sterile, it will first receive blood, which will keep it’s own microorganisms in itself.
So unless your bandaid was infected, either to the point of saturation or with an organism which would thrive in our blood and wound, then there is no need to worry.
Now, if we are talking about a piercing, for example… We are forcing something to remain in direct contact with the wound. this means that as some point the microorganisms there will have an opportunity to swim inwards and start to multiply.
But even then, if it’s a piercing and you do something like warm salted water compresses, you might just as well suck the infection away. (unless we are talking about a particularly nasty agent).
Talking about my own experience… as long as I know where the piercing had been, I am usually happy with sanitizing it for 48-72 hours in enzymatic soap on a tray on top of a speaker booming bass sounds.
I would not use anything less than autoclave for a customer, though (I used to do both things), mostly because I can never be sure of the state of it’s immune system, and on a studio the tools might get contaminated with a nasty agent from someone else’s blood.
So… what changes with an implant?
Unlike the piercing, which will still allow for external agents to be naturally expelled, an implant will keep microorganisms inside us, without means of getting them out at all.
So the range of microorganisms which could be a risk to us increases manifold! something which would be washed away long before it could evolve, now will have all the time it needs. and if you have an infection, it’s going to be really hard for your body to deal with it!
Hope this helps a bit with the Idea of the need/impact of sterilization being a spectre, not a switch! >.o
Also, to get thinking… how much sterilization is too much?
If we never get in touch with any bacteria, any tiny thing might cause a lot of harm!
Similar effect of overusing antibiotics. 