I just washed an 8 1/2 yard piece. Here is what I did to keep it under control.
1. open fabric all the way on a big flat table or floor
2. You are going to accordian pleat the fabric back and forth in about a one yard width along the whole length of the yardage. the selvage edges will be one the outsides and you flip the fabric back and forth.
3. take large basting pins or safety pins and along the selvage ends on both edges pin seven or eight pins securing all the layers together. You will pin through the selvage layers along both edges of the fabric layers.
4. Now you have a nice tidy layered pile of accordian pleated fabric. place this into a pillow case and pin it closed with several pins. more is better.
5. wash on gentle cycle. I added several towels to balance the washer. I have a front loader.
The fabric came out of the washer the same way it was after i pinned it all together.
I did double spin it to remove as much water as possible and then put it in the dryer the same way.
It was damp dry when removed and in one pretty bundle ready to remove the pins and iron dry.
It worked fabulously. I had my DH help me handle the yardage and even he was impressed the way it worked.
peace
EDIT: I did pink the two cut ends just in case of fraying
