BUY A ( POWER PLUNGER) I THINK I GOT MINE AT HARBOR FREIGHT. HAVE SOMEONE HOLD DOWN THE OPENING IN THE OTHER SINK WITH A LARGE TOWEL. IT SUCKS THE THE (STUFF) OUT AND BLOWS THE THE LIQUID THROUGH. YOU GET A REAL MESS BUT IT REALLY CLEANS IT OUT. NOW RUN HOT WATER THROUGH TO CLEAN IT UP AND FROM NOW ON ONCE A MONTH PUT A TREATMENT OF( RID-X) IN THE DRAIN WHEN YOU ARE GOING TO BE GONE. IT'S GOOD FOR EVERYTHING.