I just had a realization... I know that strictly speaking, fodder is grain grown without any growing media, but, I was cleaning my pigeons cage and he is bedded in sweet pdz (essentially sand), there are some grains in his mix that he doesn't like and they get buried in his bedding. Every now and then he has completely liquid poops (pigeon thing) and he splashes his water around, so some areas of his bedding stay slightly damp... well, the grains are sprouting and look super healthy... Since you feed grit to chickens anyway, why not take say 50 pounds of a semi-fine sand, get it damp, dump your grain in it, mix the top layer up so that the grain is mixed in, and wait, then just use a sifter to get out the sprouts from the sand. You could rinse the sprouts off afterwards or not, it won't hurt the birds.... The sand would hold water, but not so much as to cause molding or rotting like a badly draining plastic sprouting container...
You could even give them the tray of sand and sprouts and let them dig through it for the sprouts and let it be a toy as well as treat, just put the tray of sand in a larger container so that you can reclaim the sand to do another batch.