I was lucky; in California most of my work was in workers’ compensation. When a pro se worker was testifying, the judge would control the questioning, making sure to ask if there was ‘anything else’ the victim, er, the worker wanted to say. Of course, since there was no jury, and since it was quasi-administrative anyway (and we usually just had to accept all sorts of otherwise inadmissible nonsense), the worries about improper testimony were few and far in between. 