Eh, forget the mics, just use samples:
Hey! That’s a great idea.
They make little transducers that you could swallow to record you’re singing and just pull them out of your stomach when you are done tracking.
(alternately you could tape them to your neck)
You are talking about a Throat Mic, or laryngophone - Throat microphone - Wikipedia
As worn by fighter pilots, special ops teams and some motorcyclists.
As with any contact mic it tends to sound wholly unnatural as the human voice as we perceive it is an amalgamation of head, throat and chest and of course the air. Isolating one part just sounds a bit odd.
I suppose you could add some convolution processing to add back in those elements, but I’ve got to ask… Why?
Whats so nasty about microphones?
Of course a Transducer is just a word for something that converts one type of energy into another, so a microphone is a transducer, air pressure into electrical current.
Now if you could pick up the electrical nerve impulses to the vocal cords, mouth, throat, tongue, lungs and whatever then recreate a computer model of all the important bits plus then put that model into a virtual vocal booth with a further range of modeled microphones, pre-amps and compressors then you may get close to the real thing. Or you could just plonk a Mic in front of you and sing 
Or hire Professor Steven Hawking …
Or get the DECtalk DTC01
Well, I guess I’m fortunate, I have the vocal mic more or less permanently set up on a stand behind me in a treated room with a Viacoustic Flexiscreen behind it. Pretty much all I need to do is turn up channel 1 on the mixer and sing…
Screw you! That was MY line! 
but you beat me to it! 
LOL Go for it!
Hey, recording vocals with a microphone isn’t that hard. The only thing that weighs more on it is the mic and signal chain. You see, vocals are the most “focused upon” thing in music, so it you are using a dodgy mic or whatever that makes it worse, it will be really noticeable because we are listening to the words and melody. The singer has a lot to do with it too!
So beware of Cornholio when he goes to use your mic!
You say you record direct and never had a reason to bother with treating your room, well, what about mixing? Headphones? Not a great idea either. Treating a room is not all that hard to do and it can be done relatively cheap and without permanence, just a thought!!!
Peace,
Billy
P.S. A good sounding room can do wonders for a recording, I have used the room for recording electric guitar solos and the natural reverb was killer!!!