I like the Clover chalk liners, the kind with the little clicky wheel. You just have to be careful not to brush all the chalk off too soon.
I've also used the blue mark-b-gone pens and had no trouble getting the ink out. I just spritz with my water bottle and rub the water in a bit and they're gone. Never had any re-appear so far. I have an "eraser" pen that I tried once but it also "erased" some of the dye from the fabric so the lines were made visible due to that. Urgh! I stick to plain water now.