Product review (5 stars): Silent feet did the trick!
My new washer moved about a foot every time I used it.  I was afraid it would rip the hose off the wall when I wasn't home, so I had to do something.  I tried rubber cups but it still moved.  I wanted to buy the four pack, but was afraid I wouldn't be able to get the two rear cups under the feet because the instructions said they were extremely sticky and I had to slide them underneath the washer to get to the rear feet, so I tried the two pack.  Washer moves no more!  Just with the two front ones, it hasn't moved an inch.