You should try to regularly clean the inside of your washing machine as often as possible to prevent problems with future performance, and to make sure your clothes are not left smelling unclean.
Make sure not to neglect cleaning your washing machine, as mold can form in this rubber seal and result in pungent smelling clothes even after you have just thrown them in with some lovely smelling detergent.
Mold can form in the spaces of your dispenser, so it is important you clean this regularly too, as solidified detergents can cause mold to form a lot easier.