I think that there is some sort of device out there in the toy world that is supposed to replicate it,but it seemed more like a sucking type device (yes this was for a woman) and didnt look as if it would feel like oral sex. I will see if I can find it.
The only thing that comes to mind is maybe a rough hot cloth against the clit to simulate a tongue?
I say that it cannot be done. There is absolutely nothing that can replicate the wonderful sensation of oral sex. Sorry. Guess I feel kinda strong about that one.
I can tell you one thing. No matter how tongue-like some device is, flashing lights, vibrating, spitting juices, twirling doohickies - whatever - to simulate a tongue...no matter how sophisticated the thing is...it ain't going to hold you close as you cum, whisper nice stuff in your ear as you try and catch your breath or take you out to a nice restauarnt afterwards.