Douse means to wet thoroughly; to drench: “the fire was doused by the firemen with water the help of water hoses.”
Dowse is to use a divining rod to search for underground water or minerals: “He used a willow branch to dowse for water on the farmer’s land.”
When we went camping, we tried to dowse for water because we needed lots of water to douse the campfire and to douse our faces, etc. in the morning.
