How to Prevent MacBook Air Silicon from Turning on When Keys are Touched?

A friend had a mishap and needs to clean under the keys, but because the MacBook Air (Silicon) turns on every time a key is touched, it has made the process a nightmare.

When a laptop of any nature is turned off it should be OFF. It's not in sleep mode after all— that's what sleep mode is for, it can be active and ready when keys are pressed.

So this behavior has caused a great deal of trouble in the initial mishap since it caused all sorts of letters to be randomly entered on the login screen since it turned on automatically and as such he was locked out for an hour for "too many login attempts" despite him not actually trying to log in. Now it's causing all sorts of trouble since he had to remove the keys and clean under them.

He tried to properly turn it off by holding down left control, then shift and command for 7 seconds... then hold down power button, but that didn't work.

He considered removing the battery but that is impossible to do.

I only have an iMac so I don't have any suggestions. How does one stop this maddening behavior?

He and I absolutely love the Mac, but this makes no sense.