Unfortunately, recursive expunge (or purge) segfaults on modern Linux (Centos 5.2)
Reaping may not happen
The manual page talks about 'deleted' files being periodically reaped (by a process that deletes all files with names beginning .#). Of course this will not necessarily happen on today's systems.
Changes to compile
To compile on Linux, you need to change two definitions in the makefile. Set COMPILE_ET=compile_et and ETINCS=-I/usr/include/et. These are for the com_err error reporting library, which bizarrely (http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=53638) is supplied by e2fsprogs on some Linux distributions. Change these two definitions if com_err is installed somewhere else in your distribution.
An open, cross-platform journaling program.
A scientific plotting package.