Just about all pork is frozen prior to sale; shoulders, butts, spares, loins, hams, etc.; if held at below freezing temperature for 30 days, it will kill the trich worm. This is called "Certified Pork", and is now standard practice. You've eaten previously frozen pork all your life and didn't know it unless you butchered your own; and if you did it would be advisable to freeze it anyways, lol! Give them a cold water bath and let unthaw in the fridge and they'll be fine, just keep 'em cold until ready to smoke!