Although I have not used threelac ( I started my battle against candida over 10 years ago), in my own case I found that the first round of candida was the hardest to beat, and I am convinced it was because I had a serious systemic candida infection. The recovery was much slower than I had expected, although I was quite disciplined with watching my food intale etc.
What I also had to learn the hard way was that if you start feeling real good and you think you can relax more and more around your diet and take on more stress, candida can come back, as it did in my case, after several years, and then again after a few more years. The only good thing about my relapses was that I took action much earlier, and I knew what I had to do.
Good luck to you all!
Do