Mechanical and chemical tools are available to remove the obstruction and return flow to the device. For safety purposes, wear protective clothing, including gloves, goggles and nonslip shoes when attempting to clear out a urinal.
Cone-Type Plunger
If the urinal is a flush-type outfitted with a standard P-shaped sink trap, a cone-type plunger is used to clear obstructions. Place the plunger over the drain and vigorously push the plunger down and up several times to clear out the urinal. Flush the urinal to determine if it's clear. If the urinal is the seal trap variety, place the plunger over the trap, and work the plunger until the blockage is cleared.
Urinal Auger
An auger, or drain snake, features a semi-rigid spiral wire that is used to negotiate the bends of a drain to clear out a blockage. A urinal auger features a spring that is more flexible than a toilet snake to negotiate tighter bends. Feed the end of the auger into the urinal drain until it stops. Turn the handle clockwise while pushing and pulling against the clog or calcification to dislodge it. Reel the auger back in to remove it from the urinal.
Chemical Tools
Sold as a "greener" option, waterless urinals use chemicals to block odors and conserve water. The chemical sealant is heavier than urine, creating a barrier by floating on top of the urine in the trap. Over time, however, urine solids sometimes clog the urinal. A water scale cleaner containing hydrogen chloride is used to dissolve the solids. Follow the package directions for slow-draining sinks, which generally recommend pouring about 1 cup of the solution into the drain and waiting 15 minutes. Flush or pour water into the urinal to clear it out, and repeat if necessary.
Natural Alternative to Chemicals
Use vinegar and baking soda to clear out urinals and neutralize odors. Turn off the water to the urinal and pour 3/4 cup of baking soda down the trap. Pour 1/2 cup of white distilled vinegar over the baking soda, and cover with a rag for 30 minutes. The fizzing action helps dissolve deposits. After the 30 minutes have elapsed, remove the rag and pour 2 cups of boiling water down the urinal to clear it out. Repeat if necessary.