Dupe with zombies

If you time it correctly (44 items in a hopper) you can dupe the item a zombie is holding by turning it into a drowned. If this is a shulkerbox it can be really OP. If you turn a zombie into a drowned at the same time it dies with help of a timer and an campfire it drops the item but the drowned also holds the item. That one dies to and you get two times the item. A youtuber made a tutorial on this.

https://www.youtube.com/watch?v=nL3O_MuzgjA