Hot_standby WAL archiving question

Hello all,
  So I have been working on setting up an active/standby clustered postgresql 9.2 using corosync.   The corosync
documentationhas me enable WAL archiving "archive_command = 'cp %p /db/data/postgresql/9.2/pg_archive/%f'" 

  I assume so that the secondary can catch up in async (log shipping) mode before going into sync (streaming) mode.
ButI am noticing as I push data through the DB, that my pg_archive keeps growing and I am worried about running out of
diskspace. 

  Per the postgresql documentation, I set "wal_keep_segments" but I believe this only effects the segments in the
pg_xlogand not what the archive_command is processing. 

  So, since I am not keeping the archived WAL statements for long term use, is it safe to set "archive_cleanup_command
='pg_archivecleanup /db/data/postgresql/9.2/pg_archive %r'" on the master?  Also will the archive cleanup command even
haveeffect?  I only read about it being on slaves to clean-up what has already been processed. 

Thank you!

-With kind regards,
 Peter Brunnengräber