Reverse hair washing. Tried it?

This seems to be the new trend. Conditioning before shampooing is said to increase volume and make hair softer. I have stock-piled my usual products so won't be using the ones sold specifically for this routine, but might give it a go. Since having Polymyalgia Rheumatica my thick, wavy, previously greasy hair has become very dry and frizzy. Rather than employing phoenix's head-in-a-bag technique I think it is worth a try.
Has anyone tried it and does it make a difference? I usually apply a leave-in conditioner afterwards, do you think I should still do this or would it defeat the object?