i only knit face cloths (i tell people they are face cloths (not dish cloths)
I tend to knit them out of nicer cottons (mercerized) or cottons and linens, or soy silk, or bamboo..
but really, i have no control once i give them away.. If my friends or DIL use them as dish cloths.. well that what they do!
but i only knit face clothes! (i do also knit hand towels, and i have knit bath mats--but not dishcloths!)