I only spray starch fabric for machine embroidery. I use Crisp spray starch as it gives the best result, but it cost about $5.00 per can.
I do add a spray when I'm first ironing the yardage. After that I just use water. I just fold my fabric accordion style
jnto hot water to check for bleeding and take care of shrinkage. Maybe I don't remove all the sizing but I don't seem to have trouble. I don't have trouble with bias edges because I don't usually use them. In fact I avoid them like the plague.