I have a few shirts/hoodies that are quite stretchy. The materials are listed as being 65% Polyester and 35% Cotton.

I hate the fact that it feels like it's always trying to very lightly choke me. Is there any way to permanently loosen the stretchiness so that it hangs like a basic cotton fabric and doesn't "hug" my body?

Like some kind of chemical soak that would deteriorate whatever elastic compounds there are?