Missed this comment. True; binding a daemon to a rock is 'safer' than a daemonhost as (whilst not exactly safely inert) you in theory limit their ability to interact with their surroundings. It's also, taking the daemonology ritual difficult modifiers in the Black Crusade
RPG, significantly harder; because warp energy prefers living things (especially sentient living things) to inert metal. We're ignoring difficulty for the sake of the argument, but it's just a point.
If you could throw enough of them together, you should be able to shut down even a greater daemon. You only need enough of them, after all, to deal with the occasional breakout/greater daemon skulking on his asteroid.
Frankly, I'm surprised the Inquisition hasn't tried to engineer the creation of untouchables themselves.
With enough of them, properly trained, you can indeed hold of a warp entity - that was, after all, the point of deploying the Silent Sisterhood into the War In The Web.
The problem is that untouchables of worthwhile strength are supposed to be an order of magnitude rarer than psykers of comparable power, and are many, many orders of magnitude harder to find (after all, how do you locate a group whose major characteristics are that nothing weird happens in their vicinity and that they have no particular social interaction with anyone?)
The Imperium DID have the ability to clone pariahs to order. The Culexus assassin in Nemesis was a 'protiphage' - a vat-grown human - but that capability was massively rare and deeply illegal even then, and (given the usual rules of
40k) will almost certainly have been banned, lost, rediscovered in secret, lost again, and finally buried in a locked room under an Antarctic glacier with a sign on the door saying "beware of the cyber-leopard".
I'm not disagreeing with anything you say. But it's just about feasible/plausible enough that I could see an Inquisitor trying it.
And that's the worst thing. They
have.
Trying to 'drain the warp' by summoning and binding daemons, probably not; almost anyone with the knowledge to actually summon daemons in a non-suicidal manner is probably well informed enough to treat daemons as a more or less infinite resource.
But summoning and binding specific daemons purely to remove them from the 'board' - that happens all the time. Eisenhorn did it to Cherubael for petty revenge, the Grey Knights turned a daemon prince into a trophy, and there's a daemon in an Inquisitor short story who was bound and locked up to prevent him escaping back into the warp to share a secret he'd discovered with others of his kind.
