Why not let the spider do what it naturally does?
If I kill a fly and I stick it to a spider's web will the spider eat it eventually? (Just wondering maybe if I should do it I love that spider and its web).
Spiders are predators feeding on insects and even other spiders. Most spiders will only feed on live pray or pray that they have recently killed.
A live bug struggling to free itself from the web attracts the attention of a spider. Some spiders will only be encouraged to eat by that vibration on their webs. Some spiders don't need to sense that vibration before feeding begins.
Only by experimenting will you really know.