I used 3 sprayable strippers.
Citrus strip - Worked great when left on overnight. Would have probably penetrated deeper had I covered it with plastic sheets to trap moisture. Might have gone through more layers.
Napa- did good on top coat, didnt usually get to primer, but once top coat was off it knocked off primer
Kleen strip- Worked awesome, But only 1 can out of 4 sprayed without clogging itself up. I wont buy it again.
I tried the pressure washer thing too, I went back to scaping. What also work was using the 3m disc on the drill after a quick scrape. But it will fling that stuff everywhere.