If they are referring to The Maguire Programme then I would encourage your friend to give it a go. It's a 4 day intensive course in person and they have quite a high success rate if you put the work in. It is not a cure but they teach you how to be more in control of your speech with breathing techniques etc. There are similar courses out there but also a lot of charlatans so advise your friend to do proper research on the particular course and don't just read reviews from their website, go onto Facebook and join groups for people who stutter and ask the community for their reviews. If it's not a scam then they will find other stutterers who have done the course who can give an honest opinion.