Total tear down of a '87 Cremina. GH was particularly gnarly. Only hair-puller was getting the front piston rod pin out. I pulled out the ultrasonic bath to speed things up. The small parts went in plastic tubs in a 60C bath. Cafiza did its job in minutes vs hrs. Descaling also went super fast.

Good Luck... just a recommendation....clean more often Maybe try third wave water..
I hope all turns out well. be careful not to block the Pstat with junk.