that doesn't work anymore, now you need to get multiples the same of the same scroll, then you swing your weapon, and in mid swing go into your item menu, then equip the scroll that you have multiples of (best if at least 5, but doesn't seem to work with expensive items). and then drop the item that you want to duplicate. if done correctly it will automatically drop a certain amount, and when you go out of the menu you should drop more than you lost, so just pick it up.
Also you can't duplicate an item that you have more than the scroll that you have duplicates of. So to get more, get another scroll and duplicate it to the same number as the one you have duplicates of. Then drop some of one of the scrolls and the duplicate more. you should alternate which ones that you are duplicating until you have about 200 of each. is great for lock picks,and potions.