Set your washing machine to a regular wash cycle using hot water.
Start the washing machine and wait until it is full of water.
Measure out one gallon of straight vinegar and add it to your washing machine.
Close the lid and let the regular wash cycle complete.
Open the lid and wipe out the inside of your washing machine with more straight vinegar on a cloth.
Fill the washing machine with towels and set it to the regular wash cycle again. Remove the towels after the cycle has completed.