I used to reinforce my body hackle with a wire, but as I've experimented more and more, I've stopped doing it. I now tie the body hackle in at the bend (about two sizes smaller than the hook size) and wrap forward and tie off with thread.
Knock on wood, I've never had to retire a stimi because the body hackle has unraveled. Plus, I tie a lot of stimis, so the amount of time I have saved on each fly would easily cover the amount of time required to retire a fly early and tie on a new one....
"Even a fish wouldn't get into trouble if he kept his mouth shut."