Another method:
Use half muriatic acid, half water. You can buy this at Home Depot for $3 a gallon.
Do it outside.
Don't breathe the fumes.
Put the parts in the mix, and let them in for 5 minutes. Rub them with #0000 steel wool to clean any remains, and rinse in water for 1 minute.
Dry them, and prime them right away.