Wondrous Item

Varies

This Tiny, sentient piece of an enchanted gelatinous cube is harmlessly soapy, instead of acidic, and enjoys cleaning the surfaces it travels across. When found, the cleaning cube is a dehydrated, 2-inch cube. While dehydrated, the cube is inanimate and its weight is negligible. You can place the dehydrated cube in 1 or more gallons of water as an action, causing it to animate and grow in size to become a 1-foot cube that weighs 6 pounds. The rehydrated cube moves slowly while animated in this way, methodically cleaning objects and surfaces it comes into contact with. The cube remains hydrated for up to 8 hours, but can be squeezed as an action (as if it were a sponge) to dehydrate it again early.
  The cleaning cube is considered a magical object and is not a creature. It has a speed of 1 foot and can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check. It has AC 10, 10 hit points, and resistance to all damage. The cube dehydrates when it drops to O hit points, but regains all its hit points when hydrated again.
  Sentience. The cleaning cube is a sentient unaligned item with an Intelligence of 1, a Wisdom of 6, and a Charisma of 1. It has hearing and blindsight out to a range of 60 feet. It can't speak or read, but obeys your commands as best as it can understand them.
  Personality. The cleaning cube is happiest finding and dissolving dirt and other grime, and enjoys the feeling of moving across clean, polished surfaces. It doesn't concern itself with combat, preferring to continue its cleaning instead of involving itself in confrontation. If the cube finds a stray coin, gemstone, or other similar small item out of place while it cleans, it will absorb and clean the item until it's removed by a creature as an action or until it becomes dehydrated once again.