Not fished a lake with them in for a while, but used to fish a lake that held quite a few. For a while bait boats were allowed on the lake, during this period I think more grassies got caught, they seemed to like the dense concentration of bait, especially particles. If you can use a baitboat it might work on your lake, if not trying to replicate the tight, densely baited spot might work.
Bait wise peanuts, tigers and boilies all worked for me.