What was found
STRONG SMELL OF DIRTY GYM SOCKS, WET DOG ON APPROACH IN FLIGHT DECK NO ODOR WHEN AIRCRAFT ARRIVED. OPERATED APU AND PACKS FOR 30 MINUTES. NO SMELL NOTED. INSPECTED PACK INTAKES, ENGINE INLETS AND EXHAUST AND DRAINS. NOTHING FOUND, UNABLE TO DUPLICATE. NO ODOR REPORTED IN CABIN. REMOVED FOOD AND FOOD TRAYS FROM COCKPIT.