Bisect along a jagged line?

hi, i am making a rope bridge that collapses as the character walks on it. i have planks which are basically cubes and i’d like to biset into 2 halves but a straight line is a bit boring. is there a way to make use the knife or something to draw a multipoint line to use as a biset tool?

i’m a total noob so please keep it simple, thanks

just repeated clicks w/ the Knife tool, then Enter to create the cut. use “z” for the cut-through option on the Knife, if you want.

ok, i think i did it, thanks

how to close of the end after i select the bit to separe and hit P?

oh, i got that too, Alt-F