Diamond Drag Bit & Gold Leaf

I recently just picked up a diamond drag bit from Bits & Bits and am planning on using it to engrave some glass for a jewelry box. I thought I might take it one step further and gold leaf part of the engraving. Has anyone done this and can tell me their process? Did you just mask the piece off, engrave, then gold leaf the exposed area? I’m slightly worried the masking material will foul up the diamond bit. It was quite expensive.