I do a lot of Machine Embroidery. I have made seven quilts, 6 sets of towels.... I will stop bragging. Here is what you need to do.
Use a light weight tear away stablizer on the botton. The towels are thick so you don't need anything heavy on the bottom.
Use a wash away stablizer on the top. It keeps the nap from getting tangled.
Change your stictch speed (if possible) to a lower setting. I change my setting from 1000 stitches to 300 stitches (which is the lowest setting on mt Baby Lock)
After you finishe the Embroidery you will be able to tear all the back stablizer off, and just rinse the towel and the wash away disappears.
It is really very easy. :D