DwgClear
new release
purged objects are:
unreferenced blocks, empty layers, dimension styles, application entries, text styles, line types, coordinate systems, views, viewports, layouts, groups, dictionary entries, Xdata, layer filters, layer states, (P)lines with a length of 0, empty (M)texts, materials, plotter configurations
DwgClear purges your drawing from unnecessary content that is not removed from the drawing database by the AutoCAD standard _purge command.