I’d put the width (duration of pulse) anywhere from 200-300. Whatever is comfortable for you.
For recovery, I’d set the pulse anywhere from 5-15hz. You just want slow twitches in the muscle that give a massaging effect.
For explosvie strength, set it around 100-120hz and put the pulse width at 250-300. Higher width is probably better because you get more total stimulation (more stim time).