Do your research before you make these people any more money!
You will find many people who will tell you Guaifenesin did NOT work for them.
I for one, will tell you how much sicker it made me, and in nearly a year, did not make me any better, despite following the protocol to a T, and months after I stopped to get to the point where I was beforehand.
Many people will tell you that Fibro patients have issues with blood sugar, and if you do your research, you will find this has to do with hormones, not phosphates. So yes, a low-carb diet may help many people w/Fibro for obvious reasons.
Also, please note that there are a lot of links on there make this doctor alot of money, which never seems to quite make it to fund a scientific study that proves that his treatment works.
If you really want to go ahead and try it, wait until you know for sure it works (which could be YEARS, because many people w/fibro cycle in and out of good and bad periods anyhow) before you give them any of your money.

I was warned by other doctors that it didn't work, that they had done their own tests and found that the claims were false.