Phoenixtears is not the most effective form of cannabis oil for topical or oral use. I've been doing it for longer than Rick Simpson. He also uses questionable petroleum-based solvents. I use 91% isopropyl alcohol which is meant to be applied to the skin, unlike naphtha.

His oil is too viscous and lacks a skin permeation enhancer. I use 1:1 mixture of olive oil to cannabis oil, then add Cassia oil until it's at a 2% solution. The olive oil thins the medicine and allows it to be absorbed by the skin. Then the Cassia oil helps it all permeate the skin surface.

Neither I nor Rick Simpson was even the first one to make this oil. A similar recpie is in the Bible under Exodus 30:23 and uses six pounds of cannabis to one gallon of olive oil plus the essential oils.