Just purchased some myself today. LFS says that it works real great. Based on his advise, says it takes about 3-4 weeks to kill off the excess. Then it has to be cleaned up. He hasn't used any himself, but says others have been please with the outcome. I have also read another post by someone who used it and says it did the job for them. That's what made me check with my LFS. Maybe in four weeks will know the answer ourselves to this question.