I'm convinced kerosene is a formidable mixing product for making blended fuel. Search pics of the gunk I recently got out of my fuge on my last 55 gallon batch. I am making a new batch now, last speculations was the thick goo I got out was grease.
Well the oil I am cleaning now came from the same collection source, which is roughly a 1500 gallon collection site. This time I fuged 40 gallons for 4 passes hot, with nothing but oil. All I got out was some heavy grit. I then fuged 2 more passes cold, same thing.
Today I added 8 gallons of fresh kero. It's now ran 3 passes and voila, vie got that bearing grease crap going on again. When you run the grease thru your fingers you can feel grit on your fingers.
While I'm only 100 gallons into this new mix method for me, I think I'm onto something good.