there is a super easy solution to this, get a vape, lol. nah i kid i kid. res = gross but its inevitable, like gettin an itch from a hooker, its just part of the fun..... iso and salt = magic, if your res is really gross, drop 2.99 on some 99% iso and let it sit over night, it will prolly make you want to stop smoking once you see the color of the iso, but its all good.