I know it's silly as f**k but that little thought won't let me go to bed until i share it.
So as long as facehugger is symbolic inbodiment of male fear of blowjob (don't remember who said that: O'Bannon, Scott, Giger or someone else) would it be possible it can (or at least try so) implant chestburster inside the host by another way if mouth somehow locked? To be honest. i'm talking specifically about butthole. You know because anal sex is as cruel and creepy kind of rape as oral one.
Call me pervert if you want but i think sexual fears is large part of Alien's franchise.