My ds was 8 when he finally stopped. The Malem Alarms are wonderful! We got the one that vibrated and made noise. The vibration was enough to wake him without the noise. It only took 2 weeks, but we left it on for 5 or 6 weeks. Good Luck!
We used this for DS who was still wetting the bed at age 10. Worked like a charm! We also used GoodNights over top of his undies so he would still feel the wetness but not wet his bedding.