This irritated me too
If the above still leaves you clueless, just try this:
Spoiler:
1) Go to the cellar and right-click all the objects to see/hear the description. That will give you a nice hint of what you could use to "wet his whistle" 
2) If you did not leave with an object from the cemetery - go back and turn every tombstone upside-down untill you do 
3) The object from 2) should help you to follow the hint from 1) and make the man a refill
