You can wash bras in a salad spinner and wash other clothes such as socks that will fit into the salad spinner.
Add the bra or socks etc and a little soap and just enough water to cover the bras or socks or clothing.
Then spin it kinda slowly and gently imitate a washing machine agitator and move the bras or clothing around in the soapy water.
Spin it back and forth slowly and not around and around.
Then you can rinse your bras or clothing out in a sink of water to remove the soap.