function togglebutton1_Callback(hObject, eventdata, handles)
if hObject.Value == 1
brush( handles.figure1, 'on' );
brush( handles.figure1, 'off' );
seems to work fine for me using a toggle button. Strangely when I tested it at first on a scatter plot using the '*' marker it didn't work, but the same behaviour happened when I just tried on a normal normal figure so I don't know what is going in there. It worked when I used a 's' marker for my scatter plot though in both cases.
handles.figure1 is the tag for the figure itself. I never call mine 'figure1' when i am creating a proper GUI, but this was just a test so that is what it refers to. It must be the figure handle, not an axes handle.