Hi Colin,
Thanks for your interest in Syncfusion products.
You can use SetEnableDocking method of DockingManager to dock or undock a control from the DockingManager as follows,
//To Dock a control
if(!dockingManager1.GetEnableDocking(listBox1))
dockingManager1.SetEnableDocking(listBox1, true);
//To Undock a control
if (dockingManager1.GetEnableDocking(listBox1))
dockingManager1.SetEnableDocking(listBox1, false);
Refer the sample at the following link which demonstrates the above
http://www.syncfusion.com/uploads/redirect.aspx?&team=support&file=DockingManagerSample709357893.zipPlease let me know if i have misunderstood your question.
Regards
Vallarasu S.