Orchid lovers

I don't know Schultz medium but it sounds to me as if it contains a lot of peat from your description. Peat, in case you weren't aware, is vegetable matter which is almost half way to coal, so you'd expect it to have a lot of 'black bits' and small pieces of woody matter (possibly heather). These woody bits actually help to keep the medium aerated and, even though it looks messy, it would probably be best not to wash it but to use it as it is. Of course, there's absolutely nothing against making your own medium! As long as you have come up with something that works, you must be doing something right. Many orchids are epiphytes and, in the wild, grow in the forks of trees where all sorts of vegetable matter (leaves, twigs and so on) have collected and rotted down to something very like peat. Most orchids, too, have a sort of symbiotic relationship with various soil fungi. Many orchid seeds simply will not germinate unless a particular fungus is present.