Lay old towels down on the ground to soak up and catch any water puddling up on the floor.
Open the dishwasher and remove all dishes and utensils. Remove both the top and bottom dish racks.
Scoop the water and soap suds out of the bottom of the dishwasher using a plastic cup or small bucket. This step is the most important. Scoop all water and soap suds out as best you can. The better you remove the soap suds, the less chance of a repeat overflow.
Pour two cups of white vinegar into the dishwasher. Sprinkle a bit of table salt over the remaining suds in the bottom. The vinegar and salt neutralizes the dish soap and helps to prevent it from sudsing up and overflowing. Close the dishwasher and run it on a short cycle.
Keep a watchful eye on the appliance as it runs through, leaving the towels on the floor. If the dishwasher starts to overflow again, immediately turn it off and repeat Steps 4 and 5. It may take two to three cycles until the suds are completely removed and the dishwasher no longer overflows.
Replace the dish racks.