If you hold a parameter page (Playback, Amp, LFO, etc…) and simultaneously press Play (or Clear), those page settings (and setup settings) will reset to default.
Your post implies that you already know that pressing Function+Clear while in record mode will clear all the trigs for that track.
If I’m not forgetting anything, after that, you’re all set to change your machine or sample and start from scratch on that track.