I e-mailed them back in July about using their method in playschool and this is the answer I got from them:
This method is devised for use with a parent or loving relative and the child in a home environment. This way the material is shown many times during the normal day and becomes part of the daily routine. When our method fails to work well, in a classroom setting, the public thinks it is “the Doman Method” that does not work. I must advise that if you do read the books and wish to adapt the information for the classroom, that you do not say you are using our method, but your adaptation of the method.
Not that bad answer at all
Good luck in your day care and would love to know how things are going