Last time I had my 7 blinds cleaned, it cost me nearly £200 to get someone to do them using ultrasonic cleaning technology. That is fine if they have not been cleaned for years and years and they are covered in hardcore dirt/grime/dust.
I got this Microfibre Blind Cleaner to use as an "interim" cleaner, something to keep the blinds dust free and reasonably clean in order to delay the cost of another ultrasonic clean for a couple of extra years.
You take the cleaner, put the arches over two blinds, squeeze the handle gently and pull the cleaner along the length of the two blinds. It is that simple and it does a good job of taking the dust off. I did the kitchen last because those blinds had tough stains on them as well as dust. I put the cleaner under the hot tap, then pulled the cleaner along the blinds, putting the cleaner back under the hot tap every minute or two. This method took care of most of the stains.
It took about 70-90 minutes to do all 7 blinds properly, then I put the fibre cleaning head into the washing machine so it is ready to go next time.
Quick, cheap and effective, I highly recommend this duster/cleaner...