You can point a fan directly at the pot, and rotate periodically to speed up drying.
Don't worry if a little soil crumbles out. Just prep the floor for a mess.
Cut the seam on a contractor bag (Or anything that can collect any soil spilled) and work on top of that. If any soil falls, just dump it in the pot after.
If you do have loose roots at the bottom during transplanting just be nice when setting them in the new pot.