sure you can!!!
you can use flannel, muslin, what ever you want- as long as it's not going to show through
I have table runners and table cloths with wonderful drape/weight/body that simply have a layer of muslin in them instead of batting- a few years ago i made my mom a table runner with a thin batting- she did not like it and asked for one with out batting- i used muslin instead- it turned out so much better= now that's how we do most of them- you can use what you want- i would just be careful of poly blends if anything hot will be put on them---like right off the stove pans