Hehehe. I tried to tell him that too, aside from taking the pistons out and having to use a drill on the oil return holes (EricTheCarGuy has a GREAT video showing the oil return holes in the pistons of a Honda Civic. Those) and just really making them brand new and better and putting them back in.. DIY Dave obviously works a job and he is probably as hit-and-run with YouTube as I am.. I did offer to buy him a quart of the HPL EC product. He is trying desperately to clean his rings (Berrymans piston soaks for months if I've seen) and then like you said.. the pattern is it gets better a little bit, then gets worse.
I am curious to see if HPL EC would do anything on his 1ZZ-FE and like you said, he hasn't thought of fuel. The other thing could be PCV.
If its rings or compression related, HPL EC should really help it. If PCV or fuel then not so sure.. still though.. we had a thread somewhere where OP got flamed pretty darn bad, he basically made the assertion that he used a high eater oil (I believe he said he used Redline) and that fuel dilution "stopped." Now.... at first, that doesnt seem logical.. though I do remember positing (speculating, let's be grown ups here mmm-kay) that perhaps the (Redline?) "High ester content oil" maybe made things so that it was either 1. "Absorbing" the fuel so that it was somehow burned off in normal combustion... (??? Cleaned rings, higher compression???) - 2. Doing just that, cleaning stuff so that it operated to where it could keep it in check. I dont remember specifics, but OP was basically laughed out of the room. I talked to some premium oil formulators on here about it and we reached the conclusion of "I guess that's possible" - although far more likely the fuel dilution would be a separate issue...
I wonder if he will either try or take me up on the HPL EC (that is
@High Performance Lubricants Engine Cleaner, I got to tour factory twice picking it up. High Performance Lubricants is a spectacularly good company. Spectacular.)