CAD Manager Chris Wade submitted a routine to clean up drawings. If you have drawings of unknown origin, you can run this routine to help eliminate potential problems. The routine does several things: it audits, purges, and finally uses the WBlock command to export the contents of the drawing to a new file. This last step is very helpful in eradicating the drawing of unwanted nongraphical items that sometimes survive the Purge command.  You can easily add or remove commands from this routine to suit your own needs. By default, this routine explodes all entities, so consider the effects before running it on production drawings. Thanks for a flexible option to do some drawing cleanup, Chris!