[catwalker808]

Yup. It can be a tedious process. If the mount is cork with crevices, good luck, because it's resilient and dosn't break easily. Other materials are a little easier.

Here's an approach I use for unmounting or for unpotting thick heavy root balls. (not for small root balls or small messes... they're easy)
First soak the whole mess to make the roots more pliable and possibly loosen their adhesion.
Then ... and this is important ... don't attack the project from the front where the new and active growths are. Most plants grow in one general direction away from the older growths. New roots ONLY form in conjunction with new growth.

So attack from the back so that most of the damage and loss will be with the older part of the plant. With potted root balls, you will see that the newer live roots originate from the newer canes and circle to the back (due to the pot) and overlap in the back. If you attack the back, you can unwind the overlapping young roots, cut out the old roots and old or dead canes back there. Old media will either drop out or can be easily removed.

For plants on mounts, go after the mounts as much as you can ... again from the back if you can. Cut or break off pieces of a basket from the back (old side of the plant), then you will have less peeling to do. For planks, split them from the top and remove the backs. Then the mount will be much thinner and easier to cut off. For fern fiber, again remove as much as you can from the back. there may be only a little left in front which might be inconsequential. This all might help to lessen the amount of peeling and prying you have to do.
Nobody said it was going to be easy. But the point is to go as much as you can to the back area of the plant so you do your damage to the old part in ordr to loosen up the growing front part. then you do the tedious part in front.