First - I want to confirm that your method of lacquer thinner in the gas tank works great. It may even help things that are not a clogged catalytic convertor, which is what your original famous video was about. I used it on my 2012 Escape which had the "chugging at idle" problem and now it feels a lot better at the lights. It's like an Italian tuneup with more sauce

Now looking at buying a used Toyota with 2ARFE or 1ARFE and heard that if previous owner didn't change oil enough, you can get piston rings seizing up and wear in the cylinder leading to consuming oil. Is there a good treatment to use on a used 100K engine that would give a good start for a good oil change regime?