They could call it the head. Unisex is a stupid and inaccurate term.
Yes, especially if they are looking for something to call "it". There are more appropriate nouns out there. Even though "unisex" is listed as both a noun and an adjective in the online dictionary, it really sounds more like an adjective....particularly when they are talking about a...well - uh - *toilet*. (but 'ellifino)
...and I don't think the word "unisex" existed when we used hard-back dictionaries...sigh...