Hi Susan, it is a pesky job, but to do it right and know the blinds are truly clean, sadly, you must clean each and every slat individually. I prepare a bowl of very hot water with just a drop of dish washing soap and a soft cloth. Dip the cloth into the hot water mixture, wring out well and use the cloth in you hand to clean each side of the slat working across from top to bottom of the set of blinds. You'll be amazed at how dirty the blinds are. If you wring out the cloth well, you won't have any dripping and you'll not have to dry the slats as you go. It's a process as you need to clean near the little strings that hold the blinds but after you do a few you get a rhythm going and it goes quickly. If you have to stop for some reason just turn the last blind you cleaned up or down so you know where you left off. Just plan to spend a good 15-20 minutes on each set of blinds and maybe do a little each day if you have a houseful of blinds to clean.
I hang mine in the shower, wet them down with the handheld shower. Spray them with a cleaner, use a duster brush, then rinse and let drip dry.
Use the hose and nozzle of your vacuum cleanser. Choose 9ne of the heads, maybe the brush head? An close blinds and just vacuum one side then the other.
take them down and put them in the shower and spray with a degreaser cleaner. If they are above your kitchen window I just line the counter underneath them with rolled up towels, spray both sides of the blinds (still hanging in the windows) get the water as hot as I can and use the sprayer in the kitchen sink to wash them down right there, works great for me
Thank you for all the suggestions.