During initial setup of NMS we added cartridge for NMS Integration in
Foglight and brought some devices over.
1) Change your NMS configuration so that it is not sending the undesired device information to Foglight.
Navigate to the NMS Model / Network Devices and clicked on red dot with a dash to delete.
2) In the Foglight Web Console, delete the items which were previously sent by the NMS.
Web Console | Dashboards | Management Server | Servers | Data Management -> expand NMS section, then Devices, and click the Delete icon for each unwanted device which was removed from the NMS configuration.