I canít remember, did anyone on the show ever use a pencil to stake a vampire? This is how Buffy finally manages to surprise and kill Lothos in the script version of their confrontation, after heís cornered her in the school corridor; script direction says that thereís almost something like respect in his eyes as heís turning to dust (and Lothos, up to that point, has been very contemptuous and dismissive of Buffy and other Slayers).
I got the answer from mefistopheles
on LJ - there were two times when someone staked a vampire with a pencil: Willow in Choices (season 3) and Dawn in All the Way (season 6). That explains why I didn't remember it, I haven't seen either of those episodes in quite a while. I had a feeling Joss wouldn't pass the chance to use such a great idea.