The quickest way to completely remove all dropped items and loot is to run the kill command again. The all-inclusive “/kill @e[type=!player]” command will reset everything except the players, clearing most of the memory used for item and mob data storage efficiently. If you want to reset your progress completely, you’ll need to use “/kill @e” twice, once to kill yourself and all mobs, and the second time to remove everything you have dropped.