Interior Graphic Standards, second edition, published in 2010, a college text used to train architects and interior designers, you will find my name in the chapter author credits. I literally wrote the book on countertops.I checked with my mother who co-owned a construction company way back when and she said a top layer of wax might clean off, but the proper sealant is quite tough and necessary because granite is a bit porous and anything made on it would get embedded and gross.
Not to argue with you, just for the record that the typical home granite countertop should be safe, although people should test their own to make sure!
https://books.google.com/books/about/Interior_Graphic_Standards.html?id=ROlG3CTGzYQC
And no, sealants are not tough. Anything that left a protective film on granite would mark up every single time the top was used. The sealer goes down into the pores, it doesn't stay on top. Even then the sealer gets removed with cleaning which is why you are supposed to frequently re seal.