The fastest way to get them laying again is to let them raise chicks (IME). If I wait for them to stop being broody…..that will take all summer with Cochins. But if I let them raise chicks, they stop being broody to be a mama, and when the chicks are a few weeks old, they start laying again.I agree that this would be a fine idea if I wanted the hens to remain broody. But with two incubators full already I need the eggs more than I need broody hens. And when they broody like they are now they are not giving me eggs. Poor girls.
Since they are cochins, I would say that 10 months is plenty old enough to be good broody hens and mothers so if it were me, I'd give them some eggs to hatch. If I can get them moved to a separate pen, I give them eggs. If I can't - i.e., if they are intent on staying in the crowded nest boxes where the eggs are more vulnerable to getting broken - I hatch the eggs myself in the incubator and give them the chicks after they hatch. At night I move the hen to a broody pen, put the chicks under her, and lock her in so she can't leave until she has bonded to them. Once I'm sure she has changed gears from broody to mama hen, I let her out to show the chicks how to find food and water.