Vintage coffee percolator instructions. Wash the insides of an electric percolator, but do not immerse the pot in water; simply wash and rinse the interior, then wipe the exterior. Warning Before purchasing or using a Corning Ware percolator, check the government recall list. Press down on the basket until it clips into place under the heater arm. Click Here To Learn More. Some articles have Google Maps embedded in them. Measure your coffee grounds and place them in the filter basket. Just like a normal electric coffee maker, a percolator will start to get clogged up with left-over residue from the coffee. About the Author. To percolate is to make a solvent in this case, steam pass through a permeable substance in this case, coffee grounds. Replace the percolator lid. Also, as brewing progresses goes on, you should see the water shift from clear to coffee-colored.