[Kaiser2]

If the wizard shrine thing isn't implimented, then there should be "unprepare weapon" scrolls, which unprepare it, and return the diamonds to you, and the improvement scrolls yu used on it.
And praying to get blessing sremoved would be a good idea, but make it quicker, like switching gods: "The Prescense of Ogma within your weapon pushes you off the altar of Bile" "The Prescense of Ogma leaves your weapon."