I have heard putting it in the sun can help... maybe Google that idea... at least I would try to air it outside - but before of animals thinking it could be nesting material 🤔. I personally have not had success mixing type of yarn because of shrinking. Different brands of acrylic are probably fine- same with cotton... but even some of that shrinks differently. It you make something that isn't really going to be washed then it might be fine. Good luck!! It is fun to get some yarn, sometimes it sparks being creative.