I've seen them.
Look up Lyoto Machida.
That's all Hikite is, a form of trap, and often he uses as much of one as being clothed in speedos will allow.
A standard sleeve/lapel grip in Judo would at best equal a single collar tie with your other hand on his forearm, or maybe an over/under hook.
Not having clothes, having limits on what you can touch and limits on where you can hit tends to lead to modification of techniques.
BJJ takes on a different role in MMA tourneys where football kicks and stomps are kosher.
The Muay/double collar tie, is less used in Lerdrit (I think :S) where headbutts are allowed.
Rules don't define a style, but they definitely influence it.
Edit.
You can't trap a shoot.
You can sprawl, slap on Guillotine/Anaconda/Triangle or do a rice bail or sacrifice throw.
Knowing how to sprawl doesn't make him bad at WC, it makes him sensible.
Trapping is widely misunderstood, variable and not really specific, grabbing some guys collar and punching him in the head, kneeing the plex from a plum and doing an O-Goshi are all 'clinch fighting'