Yes I use ordinary bathroom silicon on headgaskets after being told by an engineer that it worked!
You can of course use whatever silicon you want on your own bike but did you ever wonder why the end of your silicon gun goes rusty, that's because your standard silicon is corrosive. If you want to be kind to your bike use automotive silicon, yes it might be more expensive but there's a reason why.
Correct...'Neutral cure' silicone cures in a different manner than, for example, bathroom sealant. More specifically, neutral cure releases alcohol upon drying rather than relying on highly corrosive substances such as acetic acid...Ian