The best answer would be to contact your swap group and ask them about soaking instead of washing.
Yes, using starch or sizing will give you that feeling of crispness.
Personally I don't like to wash fabric b4 using, but lots of people have developed allergies to the chemicals in fabric from the manufacturer and wash the moment they walk in the door. Also swappers might be concerned about shrinkage or bleeding of the fabric
which bring me back to .... contact your swap group.
hugs sue