I grew some for Max and I swear I've never seen him go so mental for anything
I used to keep in the downstairs toilet as its the only door which is always shut, and as soon as anyone went into the kitchen, he'd chase down and start meowing wildly at the door to get his grass fix
It didn't last very long though as the grass died really quickly, (I'm not really very green fingered lol), so I'm gonna get some seeds and plant them in soil this time, see if that works any better.