How big of a wood chip are we talking here? I wouldn't be too concerned about him. He should pass it without any problem, don't stop feeding him because of this. Continue to feed normally.
It was a little bit over an inch.

Why are you concerned with mouth rot? Mouthrot is normally caused by improper husbandry conditions for prolonged periods, not by a swallowing a wood chip.
because i heard that they would open their mouths a lot, and last time it got stuck in its mouth and the guy got it out with a q tip. guess its nothing to worry about?

also what i wanted to know,

how would i open the snakes mouth
are you supposed to give them those warm baths? because every time i try to put mine in it just gets out.