You can set the Brushed Data to 0 at the respective indices to deselect the brushed data. Please check the example below to better understand this:
%% Plot a surface
z = peaks(25);
figure
h = mesh(z);
brush on
%% Now manually brush the data on the figure using mouse
brush off
%% Capture the brushed elements and set them to 0
data = h.BrushData;
indices = find(data);
data(indices) = 0;
h.BrushData = data;
% Check the figure
Hope this helps!
