For simple habitual bedwetting, an alarm is often very useful. I presume you have ruled out medical incapacities which would make it impossible to learn. When I was young, I used an alarm which was wired to a pad in the bed. This was very effective, particularly when I wore no clothing below the waist, allowing urine to touch the pad quickly. I imagine that wiring to the underwear should be uncomfortable. Wireless would probably mean there is a battery in the child's underwear, which also should be uncomfortable. If these are the only type now available, I would go for it, but if the older pad type is still available, it would be my first choice. Good luck.