I need to purge a number of users from my database. Is there a better way than "one-by-one" via the Control Panel?

Yes.

Obtain and install the macro "DeleteUsers" from "delusers.tpl" at ftp://ftp.lundeen.com/pub/WebCrossing/Extras/Templates/

Call this macro directly from your browser. For example: http://mysite.com/webx/webx.dll?DeleteUsers@@

With recent versions, you can also perform a site export/import (procedure defined elsewhere in this site) using tehe xport option "The entire site except for inactive users (Inactive users are those who haven't posted and who have not logged in during the last year)".