This works!
I have many Mitch Rosen holsters. The above technique worked perfectly for all of the holsters. Use a Ziplock freezer bag and leave the gun in the holster for several days.
^+5! I've tried 7 or 8 pocket holsters and nothing compares to the Mika Pocket Holster. I had it made for for a 649 and it is perfect. Easy out and effortless reholstering (holster stays open in pocket without gun). Holster disappears in khaki trousers.
Expect to wait at least 4 or 5 months...