Unassociated regions in mdp_matrix and sales_data tables

We have a issue where there are location_ids in location table with the descriptions ****UNASSOCIATED****.These have created combinations in mdp_matrix and sales_data tables and show up as region 0 in worksheets .we want to delete these combinations and the plan is to delete such combinations from mdp_matrix and sales_data table .

is this a good plan?do we need to take care of anything else before we delete such combinations from these tables?do we also need to remove them from the LOCATION table?

the other option was to use any feature in business modeler that can prevent worksheets from showing regions of value 0 instead of creating a exception in each worksheet to not to show combinations with 0 as the region.is there any feature in businessmodeler that can be used here to acheive this?