I swear by old school tailor's chalk. I have it in red, blue, yellow, and white; between those colors I can mark anything! It always comes right out, zero problems. There's a reason they are still making that stuff after all these years...it works!
Only thing it doesn't really work for is really fine line intricate stuff - hard to get a really small point that lasts. But for drawing in guidance for FMQ...works fine!