The McGuire Programme is effective and has helped hundreds of people. It's worth considering, though, alternatives that have a similar approach. If you are in the UK there is a charity called [Empowering Voices](https://www.empoweringvoices.co.uk/) which is run by stammerers who have been teaching costal breathing for decades. Empowering Voices charge £250 for a 3 day intensive course compared to over £1000 for McGuire. They can keep the costs low because they don't make profit and get charity rates for things like venue hire. Empowering Voices have 3 courses this year.