Why drapes are cleaned in place
Lined drapery is an assembly of at least two fabrics with different shrinkage rates, usually a face fabric and a lining, sometimes an interlining as well. Take them down and wash them and the two layers shrink at different rates, the panel hangs crooked, the hem pulls up and the pleats never sit properly again. Cleaning in place, on the rod, avoids the whole problem: the panel keeps its length and its pleat structure while the soil is removed. It also means you are not without window covering for a week, and nobody has to rehang heavy panels on high Huntington windows, which is genuinely the most dangerous part of the job for a homeowner.