15 pound fluro works fine for me when targeting chummies. Seaguar gold label.
Ive also caught them with 12, 10 and 8 pound as well.
If a fish twists then teeth are an issue, sometimes it can't be avoided. My thoughts:
Take more fight out of them in deeper water before they get shallow and start thrashing/spinning. The longer a fish is flopping around once close to shore and in shallow, the more likely it will get line in its mouth.
Also try a bigger jig hook so the line is further from the teeth.
Consider a landing net so there is less time for fish to get excess line in their mouth.
What do you guys to do to prevent the chums from breaking your leader with their sharp teeth? Happened to me twice yesterday. I know there are steel wire leaders, but I don't know if they'll get spooked by them.