Get a gallon of Rustoleum rusty metal primer, and I add a qt. of black and thin with mineral spirits. Our water here is very acidic and will rust your water traps real quick. The rusty metal primer bonds with the rust and works great on rusty traps. I usual dip them twice and that will protect them for a long time.
Dipping is the only way to do conibears, you can buy different size mortar tubs and they will last a long time and are pretty cheap.