It's my understanding (NOT based on experience--so I'd wait until someone with experience confirms this) that conicals in general are loaded WITHOUT patches. You certainly can't patch them the way you do with round balls--i.e., so that the patch wraps around the projectile. That's why the conicals are of slightly greater diameter than the round balls (and also why conicals NEED to be cast out of soft lead that won't swell as it cools, like wheel weights will): conicals are fit to the bore with a much tighter tolerance, and actually have to be deformed just a bit on loading, in that the rifling sort of engraves the ridges on the conical bullet. Look at the picture above of the R.E.A.L. bullet, which shows the marks from the bullet's having been rammed down through the rifled barrel. (You can see why a harder, wheel-weight-type bullet that's expanded on cooling would be undesirable in the conical context.)
SOME people use little over-powder-patch-like things (like .500 discs of cardboard, or the like) between the powder and non-Minie conicals, on the theory that that prevents the hot gases from deforming the base of the conical, thereby giving greater accuracy. But, in my understanding, this is not necessary. And it's also not a real "patch", in the ordinary sense that you use a patch in conjunction with a round ball.
I write all of the above with this one major caveat: I get all of my information on this via the internet, and have never, myself, either loaded or fired a conical bullet. My experience is limited to patched round balls. I welcome corrections (or confirmation) from anyone in the forum who's actually experienced in this.