They didn't use a dip tank, they used one of those heated rotary wash machines. There is still some crap in the oil ring groove even after "they used a ring groove cleaner", they scratched them with something maybe a pick since there is very small shiny grooves. The compression ring grooves look OK, but I'll use a flashlight tonite for a closer inspection. They did soak the pins with oil and the move freely. I am going to inspect them better tonite, and see how the grooves look. Probably still going to have use oven clean and then buy a scraper and redo it myself. This was the last time they will get any work from me.