I've not made a quilt from ties..yet...but would treat them like any other fabric except that if they are silk they would need to be dry cleaned like you said. I have used all other fabrics to make quilts...although stretchy t-shirt cotton has to be bonded to prevent the stretching... That being said I have made MANY memory quilts...and make up a pattern depending on the variety of shirts and or colors. My Avatar is a memory quilt I made from 4 of my Dad's dress shirts..its a large throw size
Here's a link of my original posting:
http://www.quiltingboard.com/t-78602-1.htm