I've never had a rooster who liked for me to hold him. He looks really good from all of your good work. Too bad about the new injury, hoping it's not too bad. Sorry that I had not seen any of your more recent posts.
Yes, I'm pretty sure Silvadene is also called SS for silver sulfadiazine. Here is a link about it's use: http://www.rxlist.com/silvadene-side-effects-drug-center.htm
That's a pretty bad wound especially since he had no first aid treatment for a week. I would use an antibiotic ointment on the wound after cleaning it once with betadine or plain water. Is the white cream that your friend gave you a burn cream called Silvadene? That would be okay to use also...