This mod makes you unequip your boots to the nearest empty hotbar (i.e. if 1 and 2 are full, it unequips to 3) so you can use it against your toxic enemies without taking too much time. (Default key F)
This is the Expiremental version of the project.
For the newer versions: https://legacy.curseforge.com/minecraft/mc-mods/auto-unequip-boots-ne