I have washed quilt tops in lingerie bags in my bath tub. I can agitate it a bit and not get a wet floor. A friend of mine puts a plastic chair in her shower, puts a quilt top over it, spritzes it with a washing solution, and turns on the shower. she then turns it around the other side, and lets it take a shower. She lets it drip dry , or rolls it in beach towels, and hangs it over her shower door to dry. What ever works, use it. Chemicals are in everything these days.