A fixed oil is chemically the same as a fat, but is generally liquid ie. Almond oil, grapeseed oil.
I am finding that any oil [also fixed oil] works. The author of the procedure recommended indiginous oil. I agree that local oil should work better. However, I live in corn country. I am using sesame seed oil, macadamia nut oil, walnut oil and flaxseed oil intermittently for awesome results.