this is just a shot in the dark but I assume you passing in @Matter_ID and @Project_ID?

See if this select would get all int_aux_favorites that you want deleted for a given matter_ID and Project_ID.

select iaf.*

from int_maslon_matter_recent immr

join int_aux_project iap on iap.project_cd = immr.MatterNumber

join int_aux_lst_custom ialc on immr.TimeKeeperNumber = ialc.string_value and LST_CUSTOM_DEF_ID = '-10017'

join int_user iu on iu.listing_id = ialc.listing_id

join int_aux_favorites iaf on iaf.user_id = iu.user_id and iaf.entity_id = iap.project_id

where immr.entity_id = @Project_ID

and immr.MatterNumber = @Matter_ID