I haven't done much tig welding but what I did do was with a foot pedal. I just picked up a used welder and it came with a RMS-14 button instead of a pedal. Not sure how this would work as it is just a button and has no current control capability. The guy I bought it from only used the button.

I know that some people like using the finger tip control and some prefer the foot petal which I believe are basically variations of the same theme. But how do you use just a button?