Brass or stainless steel fittings resist corrosion. For PVC, use schedule 40 with waterproof PVC cement and primer.

Brass and PVC fittings can often be reused if undamaged. Compression fittings should be replaced, as the ferrule deforms during installation.

Try a flexible plastic drain snake or use a wet/dry vacuum to suction out the clog. For stubborn bends, remove the P-trap under the sink first.