Capital Airport/Visa Question

I am traveling roundt rip from the US to Beijing for a mileage trip and will not have a Visa. I know I do not have access to the 72 transit Visa since it is a roundtrip flight. I read there is a Pay Lounge in T-3, but I also read that it is outside of Security....does this mean I can not use that Lounge even if I am not leaving the airport? Please advise. Thanks!