hi there, i had not heard that it promotes egg laying, but i have fed it to my hens and they love it! one thing that i do is to soak the beet pulp in water first, because it expands when wet and i don't want it expanding in their little bellies, so i soak it for a few hours ahead of time. (it should say on the bag how much water to pulp and how long to do it for).
i actually discovered that mine liked it by accident, my alpaca was supposed to be eating beet pulp because he was losing weight like crazy, but he's stubborn and refused. so i thought 'heck i'll just throw this to the chickens'. they were *so* excited.
have you considered that insufficient light is the cause of not laying? the folks on here say 12-14 hours a day of light for maximum egg production, and with the time change and winter coming, we have less light. for me, my production is good enough with natural light, since i'm not a huge commercial farm, i am pleased with what i'm getting, even if it is less than it was a few weeks ago.
whatever you try, good luck.