I did away with sinks back in Sims 1 already, because back then you had to play efficiently. The chain was eat-toilet-shower, but sims insisted on wasting time on washing hands in between. They also insisted on washing their hands after each slice of pizza and that was with Free Will off. That drove me crazy, so no more sinks for my sims.
McTuner, as already mentioned, is a godsend, enabling me to take autonomy off sinks while still being able to include them in my builds for tooth brushing, getting water or aesthetics. (There's also a mod that stops the enforced hand washing for Sims 2, but ironically I discovered that one only this year)
