Many commercial/cosmetic "talcum powders" contain significant amounts of "oils" of unknown kind. It gives the powder a better "feel," so they say. If you're sure it's just talc powder, it should be okay for the use here, although it may not actually be very absorbent. If it's a cosmetic talcum it might contain enough "flavor enhancers" to be less than the best choice. Common "baby powders," as an example, often contain rather large additions of mineral oil and occasionally in some brands a bit of aloe.

One of the better neutral absorbents that's likely to be on the shelf in the kitchen probably would be corn meal. If it sticks to the crud, at least it won't be sticky while you wear the cornmeal, and the crud along with it, all off as you play.

Fuller's Earth would probably be an excellent material, but in my area it's a bit hard to find at convenient retailers. It may also be finely enough powdered to get into any cracks/pores in the head material and can be difficult to remove completely without a solvent of some sort. It is often used in wood finishing, but almost always with a solvent.

John