Hi.  I have been asked by an architect friend of mine to look into flaming his exterior granite walkway for the purposes of creating a less slippery surface.  I do not have any experience with this but he told me that he worked on a project in NY that involved using an acetylene torch to raise the grain on a piece of granite in order to reduce slippage.  Does anyone have experience with this and have any advice?  I did some online research and came up with a device called a jet stik sold by Granite City Tool for $2000+- that appears fill the bill, although it seems expensive for what is required.  My knee jerk response to a request like this is to grind the granite down, but my architect friend is somewhat particular (kind of goes with the territory).