My information on the flour and water formula for starch came from a novel that said in the 1700's that is how they made their starch. A weak glue would make a starch and definitely would wash out. I'm not sure how you would make corn starch starting from an ear of corn. I know that I have heard that the water left from boiling potatoes made a weak starch. When I was first married I starched my husband's military fatigue uniforms with the Niagara powdered starch. The shirt and trousers had to be able to stand by themselves without bending when placed carefully on the floor. Talk about strong cotton fabric! I think that was more my husband's idea than the US Air Force's. That marriage wasn't exactly made in heaven.