I agree about washing all types of curtains. The previous owners of our house left some rather grand, lined curtains which last autumn I bunged in the washing machine and dried on the line. They were fine, maybe a tad shorter but nothing that noticed much. I expect they would have cost a fortune to dry clean.
I'm not much into spring cleaning either but when we finish using the woodburner in the spring I do find that the downstairs part of the house needs a deep clean. DH and I do a room a day, even taking off the seat and arm covers of the sofas and armchairs and washing them. That's the easy bit, fitting them back on and zipping them up again is a mammoth task best done in the nude with the windows and doors wide open to catch any passing breeze. 