Washing
Cleaning, Laundering
noun, verbal noun, の adjective
You wash something to cleanse it by doing the washing and cleaning. You have to do the washing if you really want to get all the dirt out and make your things clean.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
電気ポットはどうやって洗浄してますか？
How do you do the wash with a hot water dispenser?