If the squib bullet is preventing the cylinder from rotating or opening, then how could a live round have gotten behind the squib?
When you say 1/4" from the end of the barrel and that the cylinder won't rotate, I assume you mean 1/4" from the forcing cone, not 1/4" from the muzzle.
Assuming all of the above is true, then there isn't a live round behind the squib. Assuming that one of the chambers is lined up with the bore properly, the solution is to drive the bullet back into the cylinder out of the barrel. I think that the alignment assumption is safe if the cylinder won't rotate--the bullet is almost certainly sticking into the chamber slightly and locking the cylinder up.
You'll need a solid brass, bronze or steel rod that is close to bore diameter. Do NOT use a wooden dowel. Don't use a cleaning rod or a pipe. Don't use any soft metal that will easily deform. The metal rod really needs to be close to bore diameter so that you engage as much of the nose of the bullet as possible so you don't just drive the rod into the bullet. Having the rod diameter close to the bore diameter also helps prevent the end of the rod from getting pointed into the rifling and damaging the bore.
Wrap a layer or two of masking tape around the rod near the end and do the same at the point on the rod that is just inside the muzzle when it is in as far as it will go. This is to protect the rifling and the crown.
The rod needs to be straight.
Figure out a way to hold the revolver firmly without marring the frame or damaging any of the moving parts.
Insert the rod in the muzzle and drive the bullet back into the cylinder. Keep the rod lined up with the bore as closely as possible. One way to do that is to build layers of masking tape so that the rod fits the bore pretty well.
Pull the rod out FREQUENTLY to make sure it is not bending or deforming and check the tape frequently to make sure it is not getting torn up. If the rod starts to bend or deform, replace it and keep going. If the tape starts to get torn up, take it off, replace it with new tape and keep going.
You can make this a lot worse if you get in a hurry or try to use a wood rod or let the rod deform or bend. If you don't have a rod that is close to the right size and made of the right material, wait until you can get one. If you don't want to take your time and do it right, then leave it alone and take the revolver to a good gunsmith.