Hi,
I have not used EFT for bed wetting with any clients, however I offer the following thoughts.
If you look into Elimination Communication (EC) or Natural Infant Hygiene (NIH) you will find the premise that babies are aware of their elimination needs from birth and this can be fostered very early. What tends to happen in the West is that it is assumed that babies don't have this awareness & hence that they have no control over their elimination functions.
Consequently they are actually "trained" to ignore this awareness & control and learn instead to use their daipers as a toilet. Over time they loose this awareness & control & so have to be "trained" back again.
Anyway, where I am going with this is that there may be some valuable tapping that can be done around having lost this natural ability, of not being to communicate to caregivers early on, of grieving over all that time spent in wet daipers because no-one understood, maybe even some deeper emotional charge around it all.
This of course may bring up stuff for the caregivers too & hence maybe some tapping for them about what they didn't know etc & maybe they will come to a different place also, which may help the whole situation.
My other thought is about how far out children's consciousness may travel in sleep. Perhaps some children travel way out, to the extent that they really do loose touch with what is going on in their physical body at times, & hence may loose bladder control in a non regular way. May be there is nothing in this idea, but then again it only takes a few minutes to try a few EFT phrases around this idea, in child appropriate language. This might be along the lines of say "Even though sometimes my dreams are just so much fun I forget to listen to my body telling me I need to pee.... etc" maybe moving towards some EFT Choices phrases about choosing to find it easy to wake up when I need to pee, even in the bestest dream etc.
Grant