Take the blinds outside to your patio or driveway and lay them on a small rug or piece of carpet.
Cleaning metal window blinds.
Remove the window blinds from the window and hang it from the hooks.
With a soft sponge clean the blinds from side to side and top to bottom.
Another preventative measure you can take is to always spray window cleaner on a paper towel or rag and never on the window itself.
Fill the tub with a couple of inches of warm water and add several squirts of dish soap.
Dip a sponge in the solution and wipe down each slat.
Wet a car washing brush and brush the blinds from side to side and then turn them over and brush the other side.
Put a few drops of dishwashing soap in a bucket of water.
To clean metal and vinyl blinds follow this method.
This keeps it from spraying backwards and ending up on the blinds where it can attract dirt and dust.
If the blinds are plastic or metal and you want to leave them in place to clean them make a 50 50 solution of warm water and white vinegar in a bowl or bucket.