I use the concentrate Sta-Flo, it's a heck of a lot cheaper than the canned and goes about 10 times further, maybe more. I mix 50/50 in spray bottle. I've never had it go bad, but they do say if you're not going to use it for a while to put in the refrigerator. I spray the fabrics, let them "soak" at least 2 hours then either put in the dryer or air dry, then iron.