As far as vinegar - clean the steel, warm up the vinegar, do it outside. The steel, if cleaned and prepped, seems to take the patina well. When you dip the blade in the vinegar, it will start to react. After about five minutes, take it out, wash it, and return it to the mix. It will get darker.
However, it is fragile so taping would be necessary if you wanted to protect the spine. Here is an experiment - which didn't work out - but the patina was nice and even.
Inventor of the world's first safety vibrating Kamisori with night light. Go to http://badgerandblade.com/vb/showthread.php/299465-A-milder-Kamisori: Inventor of the Weckisori - (thanks sychodelix)