I don't sanitize. I changed the kit if I had an infection. My pulmonologist reports no new damage to lungs after 6 years I live on farm with pigs and cows and chickens; along river, in woods, and have 3 cats and potted plants inside. Not a sterile environment. Do have an HVAC, though.
Unless you have an on-going infection, don't stress. MAC doesn't live on dry equipment. I am a retires psychotherapist, not an expert in microbiology. Just used to helping people live their best life.