The problem with the Frontier Pharmaceutical products is that they don't seem to be available. Amazon lists them, but they are currently unavailable.
Most of their push came in 2000, and it doesn't seem that they are doing much now. I have called them and they do answer the phone, but the acceptance of their line seems to be a little low.
Stone Manufacturing has a similar product line and their products are actually available. You have to look for them, but they are available.
After trying their various products, they seem to work pretty much as advertised.