Wet washing? you might as well throw buckets of water at the walls.
A extractor fan typically uses 20W so will run for 24 hours continuously for 7p worth of electricity. Run it until the bathroom is dry and window is no longer misty.
if you are unable to use a washing line or tumble drier, then put your wet washing on an airer or roll-away line over the bath, and leave the bathroom extractor running and the door and window SHUT to prevent the moisture diffusing throughout the house.
Look at the airbricks that ventilate the void under the floor, clean out the dirt, rubble and cobwebs so there is a discernable airflow.
We have a condenser tumble dryer but I take it that the moisture that creates needs ventilating itself. Perhaps another extractor in the kitchen ?
Bathroom is too small for hanging washing but I take it that we need to look at another solution.
The property was built way before anyone thought of air bricks. It is built of stone and some brick, I guess much later. Problems I guess.
One thing is that I had a flat once where we hung up all the washing and that never suffered from condensation. Now in a house hanging up far far less and even without hanging any washing, there is massive condensation.