The script in Thomas Rowlandson’s 1810 cartoon states:
“Ah! My old Friend I wish you had called
at some more convenient time but this is washing
day — I have nothing to give you but cold Fish, cold Tripe
& cold potatoes — you smell soap suds a mile!
Ah Jack, Jack you don’t know these Comforts!
you are a Bachelor!”
In Rowlandson’s image, two well fed men are seen smiling. The host is apologetic, for his guest will not get anything but cold collations, probably leftovers from the previous day. His wife and maid are seen toiling over a bucket, their hands probably raw and red from the effects of harsh lye soap. Neither of them will have the time to look to his comforts or make a hot meal, which is why he is apologizing to his unexpected guest. Since laundering was not considered man’s work, he had to “suffer” the lack of his wife’s and servant’s attentions until the wash was done.
First Boyle all the Cloaths with soap, and then wash them..” – John Harrower, indentured servant, writing to his wife (June 14, 1774)
Doing the wash in the Regency era was no small task, and housewives had to set aside two days to perform this dreaded duty, for it meant hauling water, boiling the cottons and linens, washing them with pungent lye soap, which burnt the skin, rinsing the clothes in clean water, which meant hauling more water from the well or a nearby stream, twisting the cloths to remove as much water as possible, hanging the clothes to dry, and then praying that rain would stay away long enough for the sun to perform its duty as a dryer. If one had to do laundry in a town or city, one had to pray that coal soot would not drift upon the clean clothes in a cramped back yard before they dried.

The Victorian scullery in a fine household included a copper for boiling water, a wringer, press, and ironing board.
Doing laundry was so enormous an undertaking, that unless the household were of a great size and boasted many servants, the mistress of the house and her daughters would frequently pitch in with the servants. There were chemises to be laundered, bed and table linens, towels, shirts, muslin dresses, handkerchiefs, socks, and the like. First the clothes would have to be treated for stains, the muslins and silks most delicately. After the wash had dried, ironing would commence, another laborious task.

Drying damp clothes over chair backs in front of a fireplace. Elizabeth Bennet and Mrs. Gardiner at the Lambton Inn, Pride and Prejudice, 1980
Chemises and shirts, which were worn next to the skin, were purposefully made with sturdier cloth so that these inner garments could withstand rougher treatment and more frequent washing. People tended to own more under garments for this reason. Outer clothes were subject to less frequent laundering because they were made of finer stuff, though one must wonder at the cleanliness of trailing hems, the edges of collars and sleeves, and armpits in the days before daily baths became popular, when air conditioning was just a distant dream, and when sweat must have stained clothes in a most visible manner. Is it no wonder that a majority of the Regency fashions that have survived to this day belonged to the rich, who probably wore their fashionable outfits once or twice before purchasing others?
For more on the topic: