If robots end up becoming sentient and are not biological they won’t have evolved like we have being vulnerable to bacteria, diseases and poisons/toxins and because of it our sense of smell detects bad odors, we wash our hands, take showers and have a strong aversion to things that disgust us.
Robots may just happily pick up shit, dive in dumpsters and roll around in sewage. And why wash your hands or take a shower when water could hurt you? Who even knows if they would perceive smell the same way we do.
They will have their own wash cycles/protocols because everyone knows that filth slows things down, especially joints and moving parts. Indoor ones will be programmed to stay sanitary for our sake, so they may even have UV-based self-cleaning capabilities.
They can’t perceive any sense the way organic brains do, but they can still pick up on chemical composition; I recommend that you get an air filter with a reactive/smart detection system. We already have carbon monoxide, radon, etc. detectors, after all. They’ll be really sophisticated! And they’ll cost accordingly…