I'm not so sure about the fixer. Once you start getting that sulfur smell, it's a sure sign that the thiosulfate is breaking down. It might have some life left in it, and it certainly won't hurt to try as long as you have some fresh fixer standing by in case it's shot. Toss it if there is any precipitate in the bottle. The developer is almost surely gone. If it's paper developer (which this is) give it a shot. At worst you've wasted a test strip. I'd never use anything that looked even remotely "off" on film.