Sounds good, but... shaving soap is formulated to provide the factors we require: lathering, absorption, glide, lubrication (and, of course, scent), but I've never come across a shaving soap that champions its "cleaning" powers -- after all, don't most of us shower first, or at least wash our face at the sink, before lathering, etc.? Don't misunderstand me -- there's nothing wrong with using shaving soap in the shower... remember "Save water, shower with a friend"?
At any rate, if I really want to use a soap as a "soap", perhaps the way to go about it would be to grate the shaving soap into a container, and then do the same with an unscented or complementary-scented bar of "real" soap, mix 'em together (maybe add a bit of water), form into one or two bath-sized cakes, and let 'em harden.