I will say this about recent liquids....one of the machines that I have returned to service in the 18 months or so has seen a decent amount of liquid detergent since then. When the South was shifted by P&G to 2x liquids (we were the last region of the country), I started searching out 1x leftovers, and found a 5 or 6 year-old bottle of Tide with Bleach at a CVS on clearance. That stuff added to the scrud on the auger, or so it seams, and put a funny deposit on the gold straight-vane of another machine (again, so it seemed) but other liquids have not, not before or after that. In the straight-vane machine in fact, I used an entire 100oz bottle of Tide w/Febreze with no issues whatsoever.
So, perhaps the scrud build-up problem has been quietly handled by the detergent companies?