this is how I setup tmpreaper with puppet

tmpreaper.pp

class tmpreaper {
  package { "tmpreaper":
    ensure => installed,
  }

  cron { "reaptmp on reboot":
    command => "/usr/sbin/tmpreaper -af 1h /tmp",
    user    => root,
    special => "reboot",
    require => Package['tmpreaper'],
  }

  cron { "reaptmp every hour":
    command => "/usr/sbin/tmpreaper -af 1h /tmp",
    user    => root,
    minute  => [0, 30],
    require => Package['tmpreaper'],
  }
}