I use a lot of grounds - thousands of pounds per year. We use the filters (browns) as well and they break down well with the coffee grounds (green).
I also just fling them in the yard like a monkey flinging poo. I used to do this at night but the neighbors are used to me now
Warning - if you live in the southeast, you are almost guaranteed to get black soldier fly larvae (big maggots).
I don't have a problem with them but a lot of folks don't do well with the 'ick' factor.