I really like that idea, you could have owls on the rafters letting loose on Draco (which would be pretty funny, if you're aiming for a humour-ish story) or the owls pecking at his shiny head. Ginny would have a laugh and that would really upset Draco, because he's not the type to take mockery. That could spark conversation, even if it is just two people who hate each other retorting back and forth until one decides to be civil...it's a pretty unusual punishment that could take a long time to complete--
They could clean the owl droppings without magic together!? Alone in the owlery, annoyedly interuppted by someone sending their post?