If the clog is caused by soap scum or softener buildup, heat is your best weapon.
A clogged washer drain line is a messy problem that, if ignored, can lead to flooding in your laundry room. The clog is usually caused by a buildup of lint, detergent sludge, and fabric softener residue forming a "lint snake" inside the pipe. how to unclog washer drain line
If you have a Shop-Vac (wet/dry vacuum), you can suck the clog right out. If the clog is caused by soap scum