Thanks everyone for all the info. I will share it with my guild. We had tried alot of those things but did not realize that there were differences in graphite pencils. I will try it on sample fabric now.
It is true that frixion pens will take the color out of some darker fabrics. I did stripes on a red fabric and when I ironed it the blue frixion marks came out but there were very thin white lines in their place.