Ah, but you CAN put Innospire Go in the baby bottle sterilizer! I actually called the company last year because I was confused about this. I could not find anything in their instructions that indicated whether or not one could put the mouthpiece in a steamer -- all they said was "Do not autoclave the mouthpiece" and "Do not put any part of the device in a microwave." The only thing I could find in the instructions regarding steam clean was about the HANDSET: "Do not immerse the handset in liquid or steam clean." Please tell me if you have different instructions on hand in which Philips specifically says not to steam clean the mouthpiece? Either way, I have been doing so for about six months now with no change in the function of my Innospire. Note that the article I sent you says this in Table 4, under advantages of steam-cleaning: "Can be used with metal components (e.g. metal vibrating mesh)."

p.s. adding to my comment this confirming info from Philips Innospire Go online FAQ:
'"Q. Can the mouthpiece assembly be disinfected? If so, How?
A. Yes. There are three ways you can disinfect the mouthpiece assembly which are boiling, steaming and immersion in a Korsolex® disinfectant solution.