You could use the little remote script below.
Having the script loaded, type "/logstrip" to open the file selection prompt.
Code:
alias logstrip {
  noop $$msfile($logdir $+ *.log,Selct file(s) to strip (you may select multiple files))
  if ($msfile(0) > 0) {
    var %fn = 1
    while ($msfile(%fn)) {
      var %lines = $lines($v1), %ln = 1, %in = $qt($v1), %out = $qt($v1 $+ .temp)
      .fopen ls.in %in | .fopen -o ls.out %out
      if ($ferr) {
        .fclose ls.in | .fclose ls.out
        echo -sg * Aborted (Error: $v1 $+ )
        return
      }
      while (%ln <= %lines) {
        .fwrite ls.out $strip($fread(ls.in)) $+ $crlf
        inc %ln
      }
      .fclose ls.in | .fclose ls.out
      .remove %in | .rename %out %in
      inc %fn
    }
    echo -sg * Done (stripped $msfile(0) logfiles)
  }
}

Note that I did not test the script thoroughly - I suggest to backup your original files, or do a "test run" on some copies... smile