I have lockers (full and half) set up as products- both standalone and add-on. I've added them as add-ons for various products, such as full membership. We will not be offering lockers this season, so I made them inactive. When I went to edit the full membership product, I could see they were removed from the add-on list. However, when I went to test, and add a product to cart, it was still there. Only way I could remove them was to make them inactive, and go back to each product and delete from add-on. If a product is made inactive, I assumed it would not show up as an add-on.