Simplest way is to select the route, View Dependencies, View in Main List. Select all, save to CDP. Select all again, delete. Now go back to the route, View Dependencies, see what you get in the way of "?" unknown KUID numbers. That's not a guarantee tho, since content mangler and the DLS 'bot keep tripping over each other's loose screws, sometimes content IS on the DLS but content mangler don't know how to find it and falsely reports it as unknown.