If you are deoxidizing alum. all of the parts should be stripped off that aren't alum.  I tried the crock pot antifreeze on a garage sale Supertiger .40 that was really black.  The aluminum cleaned up fairly good, but the piston/liner didn't change much, which was the reason I wanted to do it.  I still had to go and take it all apart and scrub the piston cyl. with acetone and scotchbrite to look good. The rear bearing cage was separated, likely was just that way when I got it.  Maybe the previous post K&B 3.5 was already worn out and the compression was all due to the varnish?  I didn't think dishwashing soap would remove metal.