the company has not yet developed an iron off colored chalk so bet not to try.
Have you tried the Multi Pastel Chalk pencils. They will mark on white and light colored fabrics and will erase and wash out Alto the new ceramic pencil is also good. There is another that has several colored leads like chalk made by Bohim and is available in JoAnns and other stores. Supposed to erase and wash out.
The regular pounce white chalk will come off as you work with it. I have seen it used and the demo showed spraying it with hair spray to keep it on while you worked.
The pounce is rather expensive so suggest you try it first if possible before buying it. Or get a good recommendation. I use the Multi Pastel in white and light grey only.
Remember most of the chalk will come off in the work if machine quilting as the rubbing will take it off.