Vinegar does work great for cleaning a front load washing machine.
To clean your front loading washing machine with Vinegar add two cups of vinegar to the detergent dispenser and select the tub clean or clean cycle on your front load washing machine.
If your front load washing machine doesn't have the clean cycle option then just put the settings on the highest water setting it will go to and then run the washing machine like normal to run it through a wash cycle to clean the washing machine tub.
You can also put some baking soda into the washing machine drum before starting it up to help clean the washing machine even better.