I found the tips very helpful when I was having trouble w same problem a few months ago.
I thought I will try all these steps to fix. Being busy, I did not fix anything and keep using the new Kenmore dish washer. A few weeks later the overflow got significant less. About a month later, overflow stopped completely. That dishwasher was pushing out water slower as it setteled in or the tubes got cleared w continued high flow. Either way, my over flow problem is gone now.
Waiting a few weeks for this not so serious problem may be an option for some.