This kind of spray gun produces a needle-fine stream of water at about 1000 pounds of pressure. The Krebs cleaning gun normally would have a pint container on the bottom, but for cleaning large numbers of samples I have modified the water feed via a piece of aquarium hose which is cemented into the bottom of a 5-gallon plastic bucket. The bucket hangs from a rafter in my shed so that I do not have to stop to fill the dinky pint container every few minutes. I top off the bucket with a garden hose every day or so when in use.
Needle guns are very good for working with small specimens to remove clay, dirt, and blast dust.
The Krebs has an adjustable nozzle so I can rinse delicate specimens without damaging fibrous crystals or change to a needle spray to knock off stubborn clay and clean crevices and pockets on specimens before acid treatment. Screen washing table. Handy for rinsing the bulk of dried clay and dirt off specimens with a garden hose or pressure sprayer. Note that it is built low to the ground so when washing I don't blast the specimens off the table onto the ground. I also built a raised board walkway beside this table because I got tired of having muddy shoes all the time.