There should be a menu where you can select unused devices and delete them all in one swoop. This has been a burden for when I change a devices hostname in talescale, I have to delete many devices and objects. This process is very tedious, and if made simpler could be a life saver.
Spook has an option to delete all orphaned entities.
Dont use device ids.
Use entity ids instead.
And often you can delete multiple entries in a list by clicking an icon i. The top of the list.