Mom's incontinent & bed/chair bound. She's on various med's, and it's sometimes a struggle to get her to drink enough water. Because of this, I wash and rinse her perineal area thoroughly using a perineal wash and water from a new spray bottle. After two days though, the water came out smelling musty. Even after washing/soaking the bottle with bleach solution, it smelled musty upon spray test. I like the convenience of a sprayer, but what should I add to the water to suppress/eliminate mold growth? Also, how can I clean it using natural cleansers/disinfectants without harsh chemicals?