This glitch allows you to use an item while consuming a different item within your inventory. This glitch only works with items that require additional input (has a confirmation box). The first step is to put your desired item into the quick-use slot, then start an action that has an animation(swinging, rolling, and parrying), followed by using the item during the animation(this glitch works because Dark Souls allow the player to queue up actions), after that, press pause before the confirmation box appears. Then, you will want to go choose an item to be consumed( items like binoculars and soapstone will not be consumed, making them optimal for this glitch). Then, you will use the item you've chosen to consume, causing the inventory to close and the confirmation box to appear. If you have done the glitch right, using the item you duplicated won't be consumed.