A short article by Professor Andrew Silke, whilst it may apply beyond the UK his focus and examples are British:

A rather sharp passage:
We have to be realistic about how effective it is going to be. There has never been an equivalent programme, for example, for the IRA or other paramilitary groups. And part of the reason is people don’t think it will work for the IRA. But they think it may work on Jihadis because there has been some success in countries like Saudi Arabia.
This week both David Cameron and Ed Miliband have referred to extending counter-radicalisation schemes - with mandatory participation = so this comment is noteworthy:
But one of the key issues of these programmes is they are voluntary. You can’t force people to do it and one third of prisoners referred to the Healthy Identities Programme have refused to take part