unset %p1*
unset %p2*
unset %p3*
unset %p4*
unset %p5*
unset %p6*
unset %p7*
unset %p8*
unset %p9*
unset %p10*
unset %killer
unset %the_killer
unset %the_victim
unset %knum
unset %killchan
unset %mc
unset %killed
unset %started
unset %playas
unset %game*
unset %v*
unset %mainplayer
You can do that all in one line if you want. Like:
unset %playas %game* %v* %mainplayer %etc