Deleting multiple unused waypoints with Mapsource / Base camp

Hello,

I want to clean up unused waypoints via transfer up to the device, but I do not find a way to delete existing device WP. Unless the painful job of deleting one by one in device.

I am using Mapsource. Should I go to Basecamp ? All the other features of mapsource are enough for my use.

Thanks for your help !
Horacio