Lock escalations are not necessarily evil. When you are deleting mass amounts of rows, lock escalation is OK. It is only when they occur frequently that the added overhead of escalating the locks can cause system degradation. If you anticipate that there would probably be a lock escalation, like when you are deleting all those rows, it might be more prudent to go ahead and put a table lock before the deletion starts.
If you are getting lots of lock escalations, you need to tune your database because your locklist is probably too small.
What DB2 version and OS are you using?
Andy