Milk Bucket

A bucket of milk is an item obtained from cows and mooshrooms by right-clicking on them with an empty bucket. Milk is only ever encountered in a bucket, nowhere else, and it cannot be placed down on the ground like water or lava; despite milk being a liquid, it is not a fluid block in Minecraft. Its main use is removing all potion effects active on the player. It is also an ingredient in cake.

Usage
You can milk cows and mooshrooms infinitely. Holding right-click with a bucket of milk will start the drinking sound and animation. When fully consumed it does not fill the hunger bar, but will immediately cure the player of any status (potion) effects. Because of that you can remove bad effects like poison, hunger, and wither, but also good effects such as regeneration, strength, speed and more.

Trivia

 * The milk bucket is one of the few items that doesn't stack, along with most of the tools, doors and potions, however, it does stack in the Pocket Edition.
 * If you drink milk while having nausea, the nether portal animation will show.
 * Since it cures poison, an ideal source of food would be rotten flesh followed by a bucket of milk, which will restore hunger and then cancel out the food poisoning respectively. This would only require one cow or mooshroom, and an open space for zombies to spawn on at night, or a mob farm that can spawn and kill zombies.
 * Because of its ability to cure status effects, it is a good idea to take it into an abandoned mineshaft for curing the poison effect from cave spiders.