I just took a quick Google search, and my impression would be to stay very clear of this product. From what I've read - it's a big scam - and not an easy one to get out from under, because the "free trial" gives them your credit card number, and they keep billing and billing and billing.
If you're absolutely determined to try it - don't use a "real" credit card. Use one of those prefilled cards you can get from Walmart and other department stores. The kind that when the money is used up, the company can't get more from you.