The operating frequency of pushbuttons is well below audio, BUT ... the bounce frequency is not. Further, though the edges are not razor-sharp, there's considerable likelihood of crosstalk, thanks to the nominally 5 pf capacitance between adjacent contacts, though that, again, falls into that audio range.

For ages, now, 20 ms, has been a "reasonable" timeout for debouncing pushbuttons, and that's already into the audio range.

My complaint in this particular context is not so much with the likelihood that the solderless breadboard will introduce those undesired analog parameters into the equation as with the fact that the results you get on Thursday may well be quite different than those you got on Tuesday. It makes it hard to learn anything about your circuit, which is, after all, the point of using a solderless breadboard.

In the context of working a pushbutton, I believe it's like spitting into the wind.

RE