If the soap can go in, it can get out. If the soap can go in, it's going to kill the overwhelming majority of the microbes ensconced in whatever matrix the 3d printer material is built from.
This is a non-issue.
Now, if you want to talk about 3d printer material being toxic and leaching out of the material into your digestive system, well...I don't know enough to have an informed opinion.
FWIW, I know a fair amount about microbial adhesion to abiotic surfaces and I've worked with several people who are experts on microbial sensitivity to detergents.
I would agree that it's possible 3d plastic stuff could be cleaned, but people are really bad at cleaning out simple plastic water bottles. The space inside a 3d printed object is far more complicated.
Seriously, just use a metal fork. It's cheaper, durable, trivial to clean.
How many hours of effort is it worth to reuse a plastic fork? Should I spend hundreds on an autoclave to keep the 30 cents worth of plastic clean? I hope you would agree that's a stupid waste of time and money.
Yeah, leached toxins from the plastic are bad as well. if i were forced to bet, i'd say bacteria will get you before plastic toxins, because proper cleaning would be hard.
