A WorldCraft 2 Bucket is only useful for one thing at the moment and that’s collecting milk from cows. To get milk just walk up to a cow and use the bucket on it like you would shears or a weapon. You can do this an unlimited amount of times on one cow so you should try and fence them in for an unlimited supply. Making a fence can be very trick with the animals moving around a lot so the best thing to do is complete a fence and leave a small gap open so you can lure them in with their favorite food.
Unfortunately, milk does not replenish food or health, but it will stop the effects of poison which can be inflicted by eating certain foods like spider eyes. Poison doesn’t stay around that long though and will disappear in a few second so you probably won’t even have time to cure it unless you have your milk in one of your quick slots.
Check out the WorldCraft 2 Guide Wiki for more info.
You can create a bucket with 3 Iron Ingots. Since there isn’t any Water or Lava in the game yet moo juice is all your gonna get as of now. If there is another update like the developers are talking about more things should be added that would make the it more useful with the addition of other liquids. Though there is Water and Lava in Creative Mode you wont be able to interact with it since you can have or make tools. It also doesn’t even react like a liquid should and the physics are that of a regular dirt block.
Beside making a bucket with 3 Iron Ingots you can also get it as a drop form cows. You can breed the animal for an easy supply of of what now are only really milk jugs. A long story short there isn’t any use for this item and any resources spent on making it is a waste.