I run Ultra Copper Permatex on all my cycle exhausts. You need to let it dry 24 hours before running the engine. I have never seen any of my numerous bikes smoke because of it. It is good stuff. I've had some on my Savage with a SuperTrapp for about a year and a half. If you run your bike before it dries, you'll blow it out of the connection too.

Make sure your parts are sqeaky clean. Use some solvent (lacquer thinner or mineral spirits) and some fine steel wool to get everything tidy before applying the stuff.

An update on my Permatex sealant issue.

I discovered the noxious oder I was smelling was probably the soap solution I was using for leak detection. I used a different soap today and I did not notice the odor. Turns out the Dawn dishwashing detergent I was using last week smells really bad when it gets hot.  

It looks like the adapter is leaking where it fits over the header pipe.  When I first installed the adapter, I used an automotive type "U" bolt and saddle clamp.  I snugged it up really tight and it deformed the pipe.  The section where the clamp was is smaller diameter than the rest of the adapter.  I think this may be a problem, so I'm going to try to expand the pipe and re-seal it.   I may have to cut that section out.

The exhaust flange bolts were loose again, too.