As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5281 - AFTER TAKEOFF FROM CVG RECEIVED AN AFT LAVATORY SMOKE MESSAGE WITH STRONG BURING SMELL OF OIL, CREW DECLARED AN EMERGENCY AND RETURNED TO THE FIELD. PERFORMED LEFT AND RIGHT ENGINE RUNS WITH NO FURTHER INDICATION OF OIL SMELL. BOTH ENGINES JUST HAD COMPRESSOR WASH COMPLIED WITH, SUSPECT RESIDUAL FLUID FOUND ITS WAY TO AIR CONDITIONING SYSTEM.