Hello! I used the find & replace to update my saved listings a couple of months ago--first you need to create your "new" revised profiles for the payment method and checkout areas and save them. Then go to your saved listings and hit the "find & replace" button. Select the areas that you are wanting to fix and replace them with the profiles you just created.
I hope that works for you and that I am understanding your question correctly. I don't think you can use the find & replace to fix any mention of checks or mo's in the description field though.
Good luck!