I use 1 quart of water to 3 tablespoons of organic coffee. I use it as a Liver Flush like you said during or at the end of a cleanse - I've also thought about doing one when I have a bad chemical exposure that makes me unwell but haven't yet tried that.
I usually try to do it in the morning so I can fit in 2 juices and, at other times, 2 Bentonite shakes on the rest of the day. I tend to feel pretty ropey, certainly worse that I do before doing the coffee enema, for the rest of the day.
That 1st coffee enema was particularly effective because I passed some large parasite a couple of days later, perhaps a liver fluke. I'll try with fresh coffee next time and see if I can recerate the results.