Remember there were few man made fibers back then, and most clothing was made from heavier (and some may say better quality) cotton, linen and wool, which when coupled with the differences in extraction from washers of that period versus today, meant laundry was quite wet. You needed that dryer really hot to get the laundry dried in a reasonable amount of time, so Madame didn't have a back up of laundry waiting coming out of the washing machine.
Much like some laundromat washing machines today, which IMHO leave items quite wet. Things spun in my Miele and dried in laundromat dryers, finish faster than the same amount of laundry washed there, then bunged in the dryer.
My favourite cartoon featuring a "hot" dryer of the period, shows Lucy from "Peanuts" fetching her brother's (Linus)blanket from the dryer with a long stick, then chucking it at him, Linus jumps in the air, from nearly being "burnt" from how hot the blanket was! *LOL*