would you say its not as critical as haynes make out? not sure if they put that in (special tool bla bla bla) for every car or just xe's? i normaly drive sh#tters so havent been particualy carfull before.
if its the early type, theres a sqaure hole in the tensioner carrier that a 3/8 extension bar fits perfectly. so that means you can use a ratchet or bar to twist the tensioner.
as gary said really. you need it somewhere inbetween flapping around alarmingly like an elastic band, and sounding like a supercharger. ive found the quater turn on tne lengest stretch rule of thumb a tiny bit too tight most of the time.