What was found
FLT 1098, MCO-BOS (AIRTURN BACK). DIRTY SOCK ODOR IN CABIN AND FLIGHT DECK, APU BLEED HAD BEEN ON FOR APPROX 10 MINS, ODOR BEGAN APPROX 5 MIN AFTER RAIN STARTED, ( APU BLEED AIR SUPPLY SYSTEM ) FUME EVENT COCKPIT & AFT CABIN TRIED ISOLATION CHECKLIST BUT COULD NOT REMOVE ODOR, REF LOG PAGE 4809637 FOR RESOLUTION. INFO NOTICE 2017-T015 COMPLIED WITH. NO ODOR PRESENT AT THIS TIME. MX-4 UPDATED. PLACARD REMOVED. COMPLIED WITH INFO NOTICE 2017-TO15 IDENTIFIED SOURSE TO BE THE APU. PERFORMED APU COMPRESSOR WASH & COMPARTMENT WASH, PERFORMED LEVEL A DECOMTAMINATION. NO ODOR PRESENT AT THIS TIME. ACFT OK FOR SERVICE.