Remove Dynamo objects showing in Revit

I have a routine that creates points in Dynamo to define bounding boxes. It works OK but the points are displayed in Revit as dark blue squares.
How do I stop that or clean them up?

Disable preview on the nodes which deal with that geometry, right click on the node to toggle this setting. Alternatively you can disable all geetry preview in Revit in the view menu.

thanks.