I just read a book about the uses of cayenne pepper for healing. It comes to mind because I just read it. It is by Sam Biser and Dr. Richard Schulze. This doesn't seem to have the blocked-sinus story. I can't tell you proportions to use.
Procedure is to lie down or tip head back and put the solution into nostril.
There are some versions of this where one gets the water to go from right to left nostril or from nose to throat. A turkey baster or eyedropper also works. Write me on or off-line if I've said something that is not really clear or if I can provide more info that would be of help regarding the above. The nose bleeds continued but just minor as compared to before. He had a biopsy done and they said it is not cancerous.