I use Clarkia in my enemas too. Just in case. When I can't take it orally. (like now, cause I am breastfeeding). But I am not really sure it is very smart to do it like that.
I think it is better to take the tincture orally. parasites of different kinds can live just about anywhere in our body, while enema will clean only some part of out intestinal tract. Also enema liquid does not stay in our body long enough to kill parasites, it just urges bowel movements, and everything comes out within a few minutes, as you may have noticed. So it is almost waste of the product to use it in enema if you can take it other way.
I believe you can order zapper on the net, or ask somebody here who reported using it where they have bought it.