Grungebuster washers will surely do better than the rubber washers. Grungebuster washers, Dots, and sheet material do very well with virtually all turntable parameters.
We have lots of customers who have replaced Thorens suspension springs altogether with Big Tall Tenderfoot isolation feet. Customers have also replaced Sorbothane "upgrade" suspension springs with Big Tall Tenderfeet for improved results, as well as suspension springs in AR, VPI, and other turntables.
Steve
Herbie's Audio Lab