I have read through this question ("Is it possible to use mechanical pencil instead of space pen in ISS?") and it seems that without specially made pencils, it's unlikely as there are better options. (One answer mentions they were used at one time, but have been phased out).
However, at about 02:19
into the video 2:19 in to this videoDemonstration of Acceleration Inside the International Space Station During a Reboost, it appears that there are many mechanical pencils on the left:
Are those mechanical pencils, or something else? That wall looks like writing utensils and they very much look like them!