Hi, we are upgrading our SDE along with migrating data from Oracle to SQL SDE. During migration we had to clean up domains lookup and migrate clean data to our database. Below query can help you find our all the feature classes using domain lookup. You would need SDE access to execute the query
select GIM.Name,LK.LOOKUP_NAME FROM [GDB_ITEMS] GIM
INNER JOIN (
select GI.UUID as LOOKUP_UUID,GI.Name LOOKUP_NAME,GIR.OriginID OriginID FROM [GDB_ITEMS] GI
inner join GDB_ITEMTYPES GIT
ON GI.type= GIT.UUID
INNER JOin GDB_itemrelationships GIR
on GIR.DestID=GI.UUID
where GIT.NAME in ('Domain','Range Domain','Coded Value Domain')) LK
ON GIM.UUID= LK.OriginID
edit:7/29 - fixed the link
Have you tried looking at this technical article? It shows you how you can use python and arcpy to enumerate all objects in your database to look for domain assignments.
Not sure how it ended up getting scrambled, but I fixed the link. Thanks!