I'm a fan of washing quilts after you finish them. I'm also a fan of washing quilts when they get rotated off the bed. And yes, I'm a stubborn fan of pre-washing all of my fabric!
I know that I am giving up that nice crisp look of a starched and completed quilt. But I also know that I have had the poor thing on the floor, around my quilt studio, in my lap, maybe the cat's lap (or visa versa), and have probably nibbled on something while the quilt was nearby. For sure, I have had my hands all over it by the time I'm done. Sometimes, I have used glue somewhere in the quilt, and almost always, I have basted the quilt with dissolving thread. I like to know that all of this kind of stuff is gone before I call the quilt complete!
Quilt Soap. I always use Orvus Paste to wash my fabric and my quilts. It is actually a horse shampoo that I buy in the farm and garden stores in a big jug. But you can find this in quilt stores in small amounts and it's called Quilt Soap. What is so great is that it is a near-neutral pH, synthetic soap that dissolves and suds easily in cold water. It won't strip the color from the fabric and rinses out easily.
Soak in the tub. The first thing that I do is to gently swish and soak the quilt in the bathtub. I fill the tub with slightly warm water (closer to cold, really), and add a Shout Color Catcher. Then I lay the quilt into the water and gently swish it around. If the water starts to turn color, I empty the tub and refill it with clean water. I sometimes repeat this step several times until I get clear or slightly cloudy water. Then I let the quilt soak for 10-15 minutes. I gently squeeze out the excess water and put the quilt into a large laundry basket and carry it to the washing machine.
Wash in the machine. The second step is to gently wash the quilt in the washing machine. I have a front loader and I put a small amount of Orvus Paste in the machine, set the machine to the delicate cycle and run it on cold water. When I used to have a top loading machine, I would fill it with water and add the Orvus Paste. After it got sudsy, I turned off the machine and then placed the quilt into the machine. I used my hands to gently swish the quilt up and down and then let it soak for 10-15 minutes. I would then run a couple of rinse cycles (turning the machine off to avoid agitation) and a couple of spin cycles.
Dry in the machine. My next step is to put the quilt in the dryer on low heat until the quilt is slightly damp. This doesn't take very long if you've done a good job on the spin cycles in the washing machine.
Dry on the floor. The final step is to remove the slightly damp quilt from the dryer and lay it on the floor to complete drying. I cover the carpeted floor with a flat bed sheet first, then smooth the quilt out on top of the sheet. Sometimes, I'll pin the corners and get serious about straightening the edges. Often, however, smoothing it out is good enough for me. Once in a while, I'll add fans in the room to speed the drying process.
When I'm done, I have a nice soft quilt ready to sleep under or display. I hope this helps you if you also want to (or need to) wash your quilts!