Rust Stains on OG-107 Cotton Poplin/Sateen

[AustinTX]

Does anyone know how to get a rust stain out like-new OG-107 poplin or sateen? Concerned about spotting the cloth dye. Thinking maybe some light CLR with a Q-tip? Also, what is the difference between poplin and sateen to the hand and eye?

 

[Treetopflyer]

I have gotten out numerous stains with Oxyclean. When I am not able to soak a garment in it, I will make a concentrate and apply it directly to the stain. I have even used it on "Dry Clean only" garments. Not sure how it will work on rust.