If you plan to have it here in Taiwan, I would be very interested in knowing more about it, when they get closer to realization.
I think my kids (7 and 9 years) could benefit from spending some time, living in an English speaking environment. They understand English pretty well, because me and my wife use English between us. However, when we address the kids, we use our native languages.
I also hope a camp like this would introduce the kids to the connection between the spoken language and use of the alphabet to read and write.
That would, from my point of view, help jumpstarting their introduction into my native language.
Most important however, is that they have a lot of fun (like a real holiday), practising English in a natural way at the same time.