goo gone and old tooth brush...
If you have a power washer and its outside, that will work well, just be sure to not etch the brick with the water. Also a steam cleaner will also work as it will melt the wax off of the brick. KMS idea would work as well, and its real easy when the culprit that put the markings on the wall does it for you!
Thanks for the tips on how to remove crayons. I really appreciate the help.