Smelly head
If you are just filling the bowl with fresh water you may be missing the source of the smell. You probably have outside water stagnet in the supply hose that is growing things. Visit "Peggy the Head Mistress" I think there is a link on the home page. Lots of good information. To get rid of the supply hose odor I replumed my head supply hose to feed off the sink drain. When it is time to "flush" the hose, close the sea cock, fill the sink with water and pump away. By having "clean" water sit in the hose between weekends, nothing grows, when in use on weekends, I just flush with "outside" water. With 4 of us using it, doesn't have a chance to grow anything! After you replum, it also helps to pour some vinegar down the drain the first couple times to help kill any existing bacteria in the supply hose.Correction, the link the the Head Mistress is in the experts forum.