I have Venetian blinds in my home.
I have a feather duster, but it does a terrible job, removing (at most) a third of the collected dust.
I've also used a standard dust cloth, which does a good job, but to wipe it across each blind takes much too much time.
What would be a more effective method?
I suggest you first semi-close the blinds and then dust with a cotton sock. Works like a charm. You could also use a damp cloth. If you really dislike manual work, a vacuum cleaner sometimes gets the job done.
Purchase a blinds duster. Use it.
The first thing to do is, of course, close them. I wouldn't close them completely, as it may hold up the dust in the "folds" (how can I call them?).
The next thing is to use a vacuum cleaner with the brush like this attached to the end of hose:
image from vacuumcleanershop.com
I've found a vacuum to be the best tool for this job, as long as you have a brush attachment. You still must run the brush along each slat but it's much faster than a cloth. There are even special attachments that go on a vacuum nozzle which clean several slats at once.
Take them down, leaving them fully extended. Then put them in a bathtub full of hot, soapy water. If they're really bad, include a gentle degreaser like Simple Green.
Let them soak for a bit, swishing them gently to loosen the dust and oils. Then use the shower to rinse them off.
In my case I have such blinds on a balcony looking over a big boulevard so they get dirty quite fast. The way I clean them is the following - I take down the blinds when fully extended and closed . After that I take them to the bathroom and I use my shower. My shower is with flexible hose like so that helps.
Now after you pour some water to the blinds they stick to either the floor or the walls. In case the blinds are short enough I use the wall otherwise I use the floor. Use strong flow of water and hit the blinds from one side to the other. The dust literally flows out. You may have to use some towel if the blinds are really dusty or muddy. Cleaning the blinds using this approach is much easier but it is still a challenge for my apartment as I have about 20.
NOTE: remember to remove the plastic part for turning the blinds otherwise it will constantly get in you way. Now I also remove the small plastic part at the end of the strap for lifting the blinds(after I stepped on a few and broke them :)
When I moved into my flat, I unhooked them from the window frame and gave them a shower.