I think it's a pretty risky strategy to assert a self-defense claim and not testify. I've seen a couple of cases where charged defendants tried this and were unsuccessful. I don't think it matters how many times a judge instructs the jury not to hold the defendant's silence against him in a self-defense case. The defendant has to justify the killing and the jury wants to hear from him or her.
Jim's Rules of Carry: 1. Any gun is better than no gun. 2. A gun that is reliable is better than a gun that is not. 3. A hole in the right place is better than a hole in the wrong place. 4. A bigger hole is a better hole.
no guns = might makes right