Heat your curling iron to med low and once it is hot start with 2 fabric sheets cloth and rub the iron vaci and Forth to where the cloth is hot and the smell of the fabric sheet some what melting
You notice that the sheets kinda brown of what ever residue ( hairspray, grease, gel and etc.. You may repeat this process over until liking.
Use a paper towel to wipe off the access waxs
And wipe with the face towel and your done
You can do the same with an iron to clean it too..