I was always told NOT to ever starch fabric, spray-on or liquid, as bugs love to eat it and will ruin your quilts. What I do is use sizing, which stiffens, but is not a starch. Granted, it is a spray-on (haven't found a liquid one yet), but 99.9% of us iron our fabrics anyway. I even use sizing when I iron my DH's shirts - look just as good as starching. Yes, I know, I should send the shirts to the laundry for them to do so I have more time to quilt! :-)
An ironing tip: never, ever, ever use a steam iron. Water and irons, do not mix. Water will cause an iron to leak (see Rowenta thread from last week) eventually because of corrosion of the internal parts. Those of us who "sprinkle" their fabrics and use a dry iron, have just as crisp fabric as those who use a steam iron and we have irons that will basically last forever.
Good luck with your tangles!