Im pretty sure it was meths
But whatever it was exactly, and tbh meths is about all we ever used there, the process did work. And as far as im aware, despite your if's and buts, meths is a degreaser.
Methylated spirits is a generic name that can apply to different mixes, but, in all cases, the bulk of the compound will not dissolve animal or vegetable fats.
Mineral oils, yes, but not triglycerides. Smaller esters will also be soluble, but, again, not triglycerides, which is what the bulk of any "grease" in food is.
Again, I'm not saying your method does not work, I'm just commenting that it's success will be due to the additives in the "methylated spirits" rather than the bulk of the solvent itself, and that there are more sensible ways to dissolve a triglyceride than using a product of which the bulk is not a solvent for the target whatsoever, and will only work due to additives that may, or may not, be present.
Again, I'm not saying youre wrong, so no need to fight your corner. I'm just pointing out the chemistry of it.