I used a little trick I am very proud of
to keep my sandpaper wet at all times, I used a "water spigot" designed for those old "swamp cooler fans" with an outlet valve for a 1/4 inch poly tubing....
left the red handle closed, and opened the 1/4 inch valve and controlled the flow of water to a small stream
I held it over my paper and sanded in one direction at all times
no dipping into the bucket for me
this image does not have the 1/4 valve installed