I usually use rubbing alcohol. But unplug it first. The alcohol will dry quickly onlike water based solutions so it will not short out if ou wait for a few minutes to plug it back up(As long as you do not spill the entire bottle in it(LOL)). Of course their still may be beter options.

I used to get these problems..
If you got thoes large keyboards with the numeric pad on the right and the buttons popup like a sore thumb, then it’s harder to clean.

I just press the keys real hard or take the key off and try to loosen the brace for it.. else I just keep using it and it’ll eventually go back to normal.

Alcohol can burn off thin layers of plastic from the keyboard and eventually make it unreadble after lots of contact with it..

If your son spills soda over the keyboard often, then buy a keyboard that has a flexible sheet over it (no gaps inbetween the keys) and it’s easier to clean.
Or force your son to clean it with a pencil!!

Flux.