I think the OP don't want to check TEXT isin <any line>, but <any line> isin TEXT. In this case - if a text file is used as the source - a loop is inevitable. e.g.:
Code:
  var %n = 1
  while ($read(expletives.txt,n,%n)) {
    if ($v1 isin $1-) {
      kick $chan $nick Your message contained badword $qt($v1)
      break
    }
    inc %n
  }