1. Put the item in your hand
2. Get someone to stand next to you
3. Force feed/drink them
4. Get them to run away
5. Wait until animation cancels
6. Item will still be in your hand and an extra will be spawned around the vicinity

If you duped food, the item will be at 0%, meaning you can't use it yourself. However, you can still force feed 0% food to someone else and it works fine.

• When duplicating IV Drips/blood bags, the new bag found seems to be pristine and works with every person I've tried it with.