Modifying tblContentProperty/tblWorkContentProperty Select List Items

I have the need to modify (remove), select list items that are stored in the tblContentProperty/tblWorkContentProperty tables given certain criteria are met.  Trying not to do this directly via SQL.  Is there a way to access these select list items for a particular form if I supply the ID of the parent container of the form or the ID of the element itself?  I know I can use ISelectionFactory to build a form element (select list), but can I also use it to retrieve?  I'm using a scheduled job to do this work.  And would modifying the entries with the select list items affect the drop down lists the way I think they should?  

Thanks,

Tim