Durum flour is more processed that whole wheat, so I agree that your thinking is correct.
Tobermory
Elsie, have you tried substituting quinoa for couscous? Quinoa is considered clean -- it's a wheat-free, gluten-free ancient grain (actually a seed) that I see in various clean-eating cookbooks.
For ease of preparation I suggest that you get a pre-rinsed brand (I use Ancient Harvest).
I hope this helps!
In addition to quinoa ("NOW" brands is available in many health food stores that actually sell food and not just vitamins), you could try millet (both quinoa and millet are much better than wheat, as they are alkalinizing rather than acidifying.