Have some fun with it. Soak the lot of them for a bit in some form of fuel to get the materials good and primed for the blazing. Decant off the excess liquid, let them sit for a bit. Put them into a nice safe container, such as the heavy duty oil pan you use for starting your charcoal briquets for your dutch oven cooking. Light them off, the materials should burn off fast, then smother out the flame, allow to cool and the residual stuff should come off easily. If this does not work, it will certainly be more fun! Watch your bangs, eyebrows and eyelashes.