I'm not familiar with Bounce Ironing Spray, so I can't comment on it, but I will tell you what I do. I don't pre-wash, ANY fabric I'm going to be cutting, I spray a minimum of at least 2 hours before I'm going to be working with the fabric, I use Sta-Flo starch, diluted 50/50, after the minimum time I allow for the starch to soak into the fibers of the fabrics, then I'll either air dry or put in the drier for a few minutes, when dry then I'll iron. If you spray the fabric, then iron, you're really only ironing the STARCH and not the fabric, which is why your iron will usually get all yucky brown with starch, you will not usually have that problem if the starch has soaked into the fabric, then when you iron, you are truly ironing the FABRIC and not the starch. This is my personal opinion and I'm sure that others will have their own opinion, so what I suggest is to try different tips/hints, and see what works best for YOU.