What was found
FLT 3622/3591: SMOKE IN CABIN/COCKPIT, SMOKE TOILET CAUTION, NO SIGN OF FIRE IN LAV. SMOKE SMELL NEAR APU EXHAUST AND R PACK EXHAUST AREA. C/W CLEANING OF WATER SEPARATOR COALESCERS, RAN APPROPRIATE A/C SYSTEM IN "HOT" MODE. NO SMOKE PRESENT, NO ODORS NOTICED AT THIS TIME, OK FOR SERVICE IAW AMM 21.51.13.