There's a school of thought that argues that it didn't work for Gandhi, or MLK for that matter. That both of those "non-violent" leaders' words and actions were backed by the everpresent threat of violence. These include obvious threats like Malcom X and less obvious ones like the potential for a large group of people to simply devolve into violence when provoked.

Indeed, one could possibly argue that encouraging non-violence is beneficial to the state because it effectivly reduces the threat to the state and makes alternate views easier to ignore.

I personally think it's more complicated than either view, but it's worth considering that in a larger context, non-violence rarely means non-coercive.