Here's a link with several ways to get them clean, Myrna:
No. You can clean them with a microfiber cloth.
I saw on television where they showed how. You take two small sponges and cut a slit on the side,end edge of each one. Then take a pair of tongs and slip a tong inside the slit you just made on the sponge. Do the 2nd sponge the same way. Wa-La! Put your blind between the 2 sponges on the tongs and wipe away.
As a kid it was always my chore to take down the venetian blinds and wash them in the bathtub in my parents house. Back then there were no other window treatment options but blinds so I had to wash a lot of blinds from all the windows in a three story colonial house. Ugh. Needless to say to this day I do not have one venetian blind in my house.
Thank you sooo much for all your helpful response. 😘❤️🌹