You might want to check out the exercise forum because I think there have been some posts about Slim in 6.
10 lbs per week weight loss? Highly doubtful unless you weigh well over 300 lbs with a restrictive diet and that is even pretty unlikely.
"Your old body back in six weeks" - also highly doubtful unless you aren't much different than your "old body". For me, I'd need to gain 40 lbs to get where I was when I was 18
So the claims are outrageous but that doesn't mean that it won't work to some extent.