What makes it take months to dry?
The R&F Pigment sticks don't have a drier built in the paint like Sennilier so you get pure oil paint in crayon form.
R&F is the best oil stick you can buy, but I prefer Sennilier for drying reasons, and I mix and match with both brands honestly.
I did buy an Oil Stick Blending Medium with Drier to help it dry faster. Some R&F dries fast and other take months. Their graphite takes a year to dry on wood. Their titanium white takes months as with the Ivory Black. But the blending medium with drier has been speeding up the process.