Select a stockpot large enough to thoroughly submerge the lacquered copper bowl. Add 2 gallons of water to the stockpot.
Place the stockpot over the stove, simmering the water until it boils. Once the water boils, carefully stir in 1 cup of washing soda.
Submerge the lacquered bowl in the boiling solution. Keep the bowl in the solution until the lacquer begins peeling off, which takes approximately 15 minutes.
Turn off the stove immediately, and then put on rubber gloves. Grasp the copper bowl with tongs, and then lift the bowl from the solution.
Rinse the hot copper bowl under hot water. While rinsing, scrub any lingering lacquer off the bowl using a soft cloth. Continue wearing the gloves while rinsing and scrubbing the copper bowl to protect your hands from the hot water.
Moisten another cloth with hot water. Squirt the moist cloth with 1/4-teaspoon of dishwashing liquid.
Wipe the copper bowl’s surfaces with the soapy cloth. Fully eradicate all surface grime.
Rinse the clean copper bowl under hot water. Thoroughly flush off all soapsuds.
Wipe the bowl with a towel. Completely dry the unprotected copper surfaces.