There are other organisations that are using Mandalas as therapeutic work:
The Life and Death of a Sand Mandala: http://www.youtube.com/watch?v=PSLU9PiXgRk
I think this approach has some real attributes when working with people – about community, sharing, ability to let go of things and have control over that process. However, I think to explore this area the participants have to have a level of emotional and spiritual maturity and wellness in order to contemplate this and get the most from this experience. This may cause issues within the group if all are not open and willing to participate in the same shared way. However, I still feel that this is still something worth pursuing, particularly with older people with dementia. Sand Art has a real calming and freeing quality.