Using DBMS_REPAIR.ONLINE_INDEX_CLEAN required two parameters
Object_id can be ALL_INDEX_ID, this is equivalent to zero value, or a > 0 value, this is the object_id for the index to clean.
Lock_for_wait can be LOCK_WAIT (equivalent to 1) retry until get it but there is an internal retry limit or LOCK_NOWAIT (equal to 0) don’t retry.
The function return us TRUE or FALSE
TRUE : all indexes (if several) specified were cleaned up.
FALSE : one or more indexes could not be cleaned up. Some may have been cleaned if you used ALL_INDEX_ID.
HTH – Antonio NAVARRO