Buckets (and, indeed, other such containers) are extremely useful multi-purpose objects capable of being filled with and used for the transport of otherwise dfficult to handle substances (e..g. water, oil, sand). There are many types of containers, large and small, but the bucket is considered one of the most useful. It becomes particularly apposite when faced with such pressing concerns as a fire burning out of control, perhaps caused by an attack against your property or your city or guild's fortifications (see HELP FORTS).
Syntax: DOUSE <enflamed object> WITH <container>
After you have filled your container with a suitable liquid - a bucket is recommended - you may use the contents to douse fires. Although you can use DOUSE <object> WITH WATER, for instance, it is recommended you specify the container to utilise since it is more accurate. This is particularly important where speed is of the essence and you find yourself with many buckets, faced with multiple fires. Each iteration of the DOUSE command will broadcast some of the container's contents onto the enflamed object; hopefully reducing the ferocity of the fires 'til the flames are entirely doused or you have exhausted your supply of liquid.
Read through HELP CONTAINERS to review the commands required to fill and empty buckets and other containers; and HELP FIRES to learn more about fires. See also: HELP WAGONS and HELP VEHICLES.