I tried to err on the side of excess and used about 4 cloves of garlic to 2 cups of water. I got to the point where I was sick of peeling garlic so often so I just chopped it up finely with the peel still on, then added boiling water and covered the container with a lid and let steep until it was room temp. Then strain and mix in a heaping spoonful of plain yogurt. It's important that the water not be too hot or it will kill off the beneficial bacteria in the yogurt.
p.s. I never found that it made much difference if I held in the water for a while or released it right away. But I always took the enema lying down and massaged my belly to make sure it got into the transverse and ascending colon which is where most of the yeast was living.