I have excellent luck with Thoroseal and the other Thoro products. They have been used for many years in commercial, residential and concrete restoration. It is messy to apply (like pancake batter), should be applied to a damp wall and woorks well as a waterproofer.
I know Radonseal was more recently developed to reduce radon gas, but do not know how effective it is when used for a different purpose.
Is there any way I can contact you or vice versa to pick your brain on my dilemma; I am being told to spend thousands $$$$$ and I cannot verify the info! Dogdoc email or call , can I post my number here? please