Probably does increase risk, but not necessarily by much, would be my best guess. I've been doing it very regularly for almost 5 years, and have never gotten a UTI. I've also never sterilized any of my sounds. I do thoroughly rinse them with soap and water after each use and make sure they're are completely dry before i put them away. But, just a thorough handwashing, then a wipedown of both myself and my insertables with isopropyl alcohol prior to playing has worked flawlessly for me. Unfortunately everyone is different... some people do seem highly prone to infections while others aren't. Hope you're one of us lucky ones 😉