I have the same leaks and it drives me nuts. I haven't figured out which way I want to fix it yet. I may try that exhaust cement stuff just for the hell of it.
I think a better way to pin point exhaust leaks is to go buy a $10 stethoscope from autozone and use that.
I was able to find 2 leaks at my header I was wondering if anyone has come across also. I found that I have a leak on both sides in the exact same spot. See attached photo.
The leak is where the pipe goes into the "flange." It isn't a very large leak, but it is def a leak. I just found it to be weird that both sides are leaking in about the exact same spot. Has anyone else found the same thing?