1.when in the shower, a woman might take the shower head and change the setting so the water comes out of about 4 holes
and this woman might lay down on the floor or whatever and spread her legs and take the shower head and put it up against her clit sometimes causing an orgasim to take place
2. shower masturbation
3. masturbation that a woman can use during her period that cleans the vagina and does not get her hands dirty.
"why does the water sound like it is comming out harder?"
"maybe she is massaging her back"
"maybe that is why she is moaning!"
"oh crap she is using the water method again!"