Hmm.. I don't believe I stepped up on my soap use just because I was dry brushing... I just added dry brushing to my health routine, and that was that. :)
Dry skin really likes oils, but doesn't always like moisturizers. Oils tell the skin to keep its moisture, while moisturizer tells it that it doesn't have to. During the winter, not that it gets all that cold here in So Cal but still, ;) in the winter I use an almond oil that they use in India to keep my skin happy and supple immediately after bathing.