Outside of using our app's Modify Products tool along with the Advanced Modify add-on ($20/mo), you can also deactivate products manually directly in Facebook Catalog Manager.
To deactivate a product in your catalog manually:
Go to Catalog Manager and select the catalog that contains the product you want to deactivate.
Hover over the product that you want to deactivate and select the box that appears in the top right. You can select multiple products. Remember that you won't see this option if you imported your products from an ecommerce partner.
Select Deactivate Delivery.
Your products will be deactivated within a few minutes and customers won't see them anymore.
You can switch between Activated, Deactivated and All Products to see which items in your catalog are activated or deactivated. Deactivated items appear shaded and you can't use them for ads or commerce. If you want to use deactivated items later, you can activate them again.