Not for release rel-2-4-7 and the rel-2-4-patches version of WeBWorK. In the soon to be rel-2-4-9 which is currently the "trunk" version of the svn repository, it is possible to click a "select student" with a single button. You will then need to unselect instructors (including yourself) and others whom you do not want to delete. (I don't believe you can delete yourself, even if you forget. :-) )
The trunk version is quite stable and has several improvements, particularly for administrators, over the 2.4.7 version. It's been in use on hosted2.webwork.rochester.edu since the beginning of the year and is now used on the new MAA server at courses.webwork.maa.org.
for details on converting to subversion which is now the preferred mechanism for new releases of WeBWorK.