Washing Machine

I left a wet towel in the washing machine while our house was being remodeled and we were moved out, for 8 weeks. I can not get the musty smell out of the washing machine. It does not cause the clothes to smell musty when I wash them. When I open the front door to fill the machine I am hit by the oder, even though I wipe it down with a paper towel and leave the door open for a day after the last use. Is there anything I can run through the machine to solve this problem?
Thank you,
Judy