The problem with self-portraits using paper negatives in pinhole cameras is the exposure time. I rate my paper negatives' "speed" at EI=3. I use Freestyle's Arista grade 2 RC paper for negatives; a 100-sheet box of 8" x 10" paper costs around $35us. In bright sunlight, a typical portrait may require 30-45 seconds exposure time. So you have the classic problem of keeping your head very still, and keeping your eyes open long enough to register detail. Also, paper, having a blue-only sensitivity, will render skin tones darker than normal, so you want to overexpose a bit to render a normal tone.
You can contact print paper negatives just fine. I like to contact print onto a fiber based multigrade paper; this gives you a fine print quality, and the ability to adjust the print contrast as needed to adjust for problems with negative contrast. I use my condensor enlarger as a light source for contact printing. Heavy sheet of glass to sandwich the two sheets of paper together. I never contact wet the negatives wetted with water, always dry. And I never oil the backside of the negative, or try peeling the emulsion off the paper. I don't see the point; they print fine onto silver paper; perhaps alternative processes requiring UV light may need a more transparent negative, hence the alternative contact printing methods.
~Joe