I'm sure the plants will absolutely love it and the grass seeds will be ancient history.
My only concern was prep for application is going to be - 'aromatic' at the very least. Fermented grass clippings/rabbit poo is bound to have a strong odor.
Maybe a cheese-cloth type strainer over the top will make it more manageable? Honestly, I'm trying to think ahead & suggest an option that might help...
NO problem, I understand. I've dealt with enough soupy rabbit poop in my time to not really be worried, but I get where you are coming from.