I'm coarse and low porosity as well. The whole issue is that our shafts are closed down so it difficult for moisture to get into our hair so that when we moisturize (seal) with things like QB, etc there's really no moisture for these products to lock in. The solution is revising your conditioner regimen, particularly your leave-in's to give you enough hydration so that when you do moisturize it can do its job which is to prevent moisture loss via evaporation.
Interesting. My daughters hair typically likes heavier products but the BM products work great on her hair. I haven't tried them yet on her hair when it's down and out though...only on styles. I say if you really want to try it go for the sample. I'm not sure how much the moisturizer same is, maybe $5? Then again you would have to pay shipping as well. Hmm.