Pour a small amount of ammonia or denatured alcohol either directly onto the hairspray or onto a nylon scrubbing pad for wall application.
Rub the nylon scrubbing pad through the ammonia or denatured alcohol on the hairspray vigorously. Use a circular motion, working in small areas while the ammonia or alcohol soaks the rest.
Rinse the area well with plain water and repeat if necessary until the hairspray is gone. Depending on the level of buildup, this may take several applications. Dry the tile between cleanings to test for remaining sticky areas or missed spots.