Most blinds should not be machine washed unless the manufacturer specifically states that the fabric is removable and washable.
Roller blinds are generally wiped clean rather than soaked.
Roman blinds sometimes have removable fabric sections, but many lined styles require specialist cleaning to avoid shrinkage or distortion.
Venetian blinds and shutters should be cleaned in place rather than removed.
Day & night blinds are best maintained with gentle dusting or careful wiping because the layered fabric can be delicate.
Using too much water can damage mechanisms or affect the finish, so light cleaning is usually safest.