Well, actually it's a modified Draco Malfoy torso (most likely) as Harry Potter wouldn't likely travel around wearing Slytherin colours (bar being polyjuice-disguised as one). If there is a prime candidate for "useless multiple figs," Harry Potter is surely the posterboy, and it's rather likely that I'll do a post or two on his various non-Harry Potter uses in my LEGO collection... but it'll have to wait until I'm back in Boston, since that's where most of my Harry Potter figs are these days.
(On which note, I leave Alberta on Sunday and after a couple nights' stopover in Toronto with relatives, I'll be back in Boston a week from today. Expect updates to be sporadic at best for the next couple weeks.)
This post, in the meantime, is not about the usefulness of Harry Potter parts, as such, but about the attractiveness of a specific Harry Potter part, once modified. As one can see from the picture above, I've modified an existing Slytherin torso by removing the Slytherin shield, producing a "sweater and tie with green highlights" torso. Admittedly, one's LEGO collection probably doesn't need multiple "sweaters with tie" but one or two are easily incorporated into a Town scene. Even if the modified torso is no more useful in high quantities than the original version (and, personally, I think it's more useful than the original), it's still a rather handsome piece.
As to the mechanics of modifying the torso, I simply used a normal pencil eraser. The abrasiveness required to remove graphite from paper is about the same as that required to remove the printing from a LEGO piece, although a lot more elbow grease is needed. The fact that you can find erasers handily positioned on the end of pencils also made it rather easy to exert the necessary control that would not have been possible with a stand-alone eraser--since, of course, I didn't want to remove ALL the torso's printing.