Wasn’t there an experiment of farting in a lab and contamination of petri dishes?
Something in the lines that at least wearing one layer (underwear) is enough to prevent contamination.
Wow, there are plenty of studies, this is the funnies one I found:
https://pmc.ncbi.nlm.nih.gov/articles/PMC1121900/
“Our deduction is that the enteric zone in the second Petri dish was caused by the flatus itself, and the splatter ring around that was caused by the sheer velocity of the fart, which blew skin bacteria from the cheeks and blasted it onto the dish. It seems, therefore, that flatus can cause infection if the emitter is naked, but not if he or she is clothed. But the results of the experiment should not be considered alarming, because neither type of bacterium is harmful. In fact, they’re similar to the ‘friendly’ bacteria found in yoghurt."
Start with building a very cheap computer with your kid.
You can buy parts for cheap or sometimes get them for free from e-waste processing places. You can do the screws to the case, but let the kid put the parts in place while you explain what they do.
Parts are easy to handle, just make sure to not damage the components as they look cute and are a bit malleable, but put too much pressure you can destroy it (not sure a kid will be strong enough for that).
It is as easy as building Lego, or putting a cartridge on an old console. This will help to make the computer less scary.
Make sure that you can do it yourself and test the parts first before involving your kid, so they do not get too frustrated if it fails.
This will cover hardware.
You can also help them to install the OS.
After, make a list of the programs you want your kid to be aware of: calculator, place to write text, anything you think it will be useful. Take some time to explain them, and do some exercises with each - let’s write a letter to a friend, etc… Let them play around with it without judgment. (remove things you don’t want them to use).
If you want to give the child some background in how software works, Logo was very popular with kids at the school.
Logo is this little turtle that you give orders, similar to imperative programming language used in most softwares.
And the turtle would draw a green line on the screen.
There are plenty of options for software that provides that, here is an option https://apps.kde.org/kturtle/
And, of course, try to break these in multiple days, building a PC, installing OS and playing with programs can be overwhelming for some kids.