Voice/Neutral Accent Training
I realise you posted this sometime ago, but neutral accent training modules is somthing that we do at The Central School for Speech and Drama, along with other types of voice training, e.g Spoken English courses for ESOL speakers. Our voice specialists have delivered this training to many different organisations. We may be able to offer you this to your employees and your trainers as part of our Knowledge Transfer project. (We have funding for this from the LDA and HEFCE so there would be very little cost involved) Have a look at my email under the "training and development" section for more details.
Central School for Speech and Drama.