My husband smokes. This is how I wash quilts. It may be a bit of work but I have not broken a seam yet. Knock wood.
I line my bathtub with a clean, unfolded, white sheet. I fill the tub full enough of cool water to cover the sheet and the quilt I'm going to wash, then add 1/2 cup of sudsy ammonia to the water. I put the quilt in the tub getting it completely wet. I'll add more water if needed so I can 'swish' the quilt in the water. Once the quilt is wet I'll let it soak for about 10 minutes then I'll drain the tub. Once the water has drained I'll refill the tub with cool water to rinse. I usually do 2 complete rinses or until the water is clear. Once I'm done rinsing I press as much excess water out of the quilt as possible then I get one side of the sheet even with a side of the quilt and gently roll the quilt and sheet together 'jelly roll' style, all the while gently pressing water from the roll. Once I have as much water out of it as possible I hang it over 2 clothes lines. I carefully unroll one end and attach the sheet to the clothes line. I then unroll the rest of the quilt/sheet to attach the other side of the sheet to the other line, making a hammock to support the quilt, I spread the quilt out in the sheet as much as possible. As more water drains off, I spread the quilt out and fluff it periodically until it is dry.
If you have someone to help hang it, it is an easy job, otherwise plan on getting wet.