We do same as RobGallagher plus pull the garboard plug, clean filter screen on manual pump and electric pump housing, stuff rag in manual pump outlet to keep the unknowns out. Last year we started a full interior wipe down of every molded surface with Lysol wipes. In one day all the gamey smells were gone.
Being that we maintain the boat for the owner rather than own it, we've come to realize nobody else was doing anything, although the owner thought the yard was on the job.
Our approach is do it now, rather than forget it later.