If the stain refuses to budge, soak a heavy-duty paper towel with straight peroxide laying the towel on top of the stain. Cover the towel with plastic wrap to prevent the peroxide from drying out quickly. The towel holds the peroxide on the surface giving it time to dissolve the stain. If that doesn’t work, mix a paste of straight peroxide and baking soda. Allow the bubbling to subside. Apply to the stain and let it set. Re-spray with peroxide as it dries out.
Shaving cream sprayed on stains also does a good job removing them. If your grout is colored test an inconspicuous spot first. Tile stores now carry a cleaner stick that resembles chalk. It is safe to use on colored grout and works wonders. After you remove the stains from the grout, seal them.
Let me know if you have more questions.