We are also on a septic system. My husband has been dip starching his shirts (and some of my yardage
) for almost 40 years without ill effects. This is how he does it: mixes a 50/50 solution of StaFlo and water. He launders the item as normal, takes it out of the washer wet, immerses it in the starch mixture, wrings it out & throws it in the dryer till it's damp then irons. If it gets too dry, he spritzes it with water as he irons. When we were first married & he said he wanted me to starch & iron his shirts as I never did it to his satisfaction, he took over. Works for me.
I'm a pre washer, but I don't dip starch all my yardage, just if the pattern has a lot of bias edges, or I'm making a really large top that will be tugged around as I stitch. Otherwise I just use the 50/50 mixture in a spray bottle & lightly spritz.
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