I first tried an "environmentally-friendly" adhesive remover which had the same effect as pouring water on the steps. My next time around, I used a product called "Jasco Semi-Paste Adhesive Remover." I applied it in a thick coat with a wallpaper brush and let it sit for 15 minutes as recommended by the manufacturer. I then used a pressure washer to blast off the dissolved adhesive. I had to use a few coats and a putty knife to take off the glue that had been applied too heavily, but the stairs came out looking like brand new!
A warning...this stuff is potent! When using a pressure washer to hose off the residue, use safety googles and cover up any bare skin.