My Mother has a tiny amount of a drawing salve that my Grandfather made. We don't know the recipe, except that it was made with an extra large measure of STINK!
But man did that stuff work.
Try the drawing salve. If it doesn't work, just let nature take its course as Nick said.
Nitrocellulose isn't really poisonous. Some of the residual solvents may be, but they are in tiny amounts.
The LAST thing you want to do, though, is to try to dissolve the stuff. Toluene will work fairly well, but it will also strip every last bit of oil out of your skin and likely give you one hell of a case of chemical contact dermatitis.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.