I am allergic to corn so have to wash all new fabric, to get the sizing off, and can't use regular spray starch. I water down the Terial and use in place of starch. You can play around with the ratio but I've used 3:1 and it still works very well.
I found potato vodka with water works as a starch so am planning on trying that next though, to see if I can save a little bit of money.
I also use London Laundry Ironing and Sizing spray, as a light starch/sizing. It's unscented and I've not had any reactions to using it. It's around the same price as Terial but doesn't work as well when watered down. And I can only find it on Amazon. But it doesn't seem to attract pests so it'll work for me.