While skimming oil for another round of washing there is always a bit left behind. That oil - fatty acid barrier is not always distinct and one must make the decision when to stop and leave the leftovers for later.
The leftovers get dumped into my reclamation oil jar, which was recently washed up a few times and considered done. Only thing is that the result was terribly cloudy, still holding onto those fatty acids and probably some water as well.
I've had this idea mulling about that I could filter this stuff...
The funnel tube is plugged from end to end with a cotton ball. The funnel is friction fit into a piece of corrugated cardboard. Hi tech, huh? ;-) Well, it works so absolutely perfectly well! That cloudy mess is coming out crystal clear!
It is taking time--a few hours to get less than the two ounces you see here, but I see no worries. This looks like one of those set 'em and forget 'em procedures.