Three consequetive enemas sounds about right. Your own body is excellent about telling you when you have had enough. If you get that "sick" or "I don't want to do another" feeling, then stop. More than five enemas could lead to electrolyte imbalance and over hydration.
For a good cleansing program, you may repeat the three enemas per day for perhaps up to a week. After that, just for periodic maintenance, another three enemas whenever you feel the need should be sufficient.