What mesae said is good advice. You really don't need washout on most trainer wings.

However, I always make sure that every one I work with doesn't have washin. You'd be surprised how many "flatbottom" wings show up with drooping TEs out at the tips. It usually comes out just running an iron over the covering along the top while holding just enough twist to see wrinkling. And while I'm doing it, I usually put in just a hint of washout. Just to hedge the bet against it coming back.

BTW, what is the airplane?