The Sonic Duo is simple enough to use for everyday cleaning: add water up to the 1:7 water fill line of your reusable bottle, then top it up with some of the concentrated detergent (either hard floor or carpet, depending on the surface). Next, screw the lid back on and click it into the unit so it stays in place. You can remove the bottle for refilling at any time.
To test its hard floor cleaning claims and ease of use, we put the Sonic Duo through our traditional steam mop test method. We found the vibrating mop head easier to manoeuvre than many other traditional steam mops, which are sometimes tiring to move around the floor. Controls for speed and spray were also easy to access, and the mop pad was easy to attach to the steam head using the hook and loop design.
We also tested how well the Sonic Duo removes stains on vinyl including mustard, a muddy footprint, tomato sauce, red wine, coffee and soy sauce. Results were impressive overall. The Sonic Duo was excellent at removing all stains apart from mustard (poor performance) and coffee (only OK).
To see how well it polished sealed wood floors, we gave it to a staff member to try in her home. She also found it easier to manoeuvre than the steam mop she already owns.
"The action was good as you did not have to go over the same area a number of times scrubbing off a dirty mark," she said. However, she was uncertain exactly how much polishing liquid to use, and she found the array of different cleaning pads for cleaning and polishing confusing at first.
Another selling point of the Sonic Duo is its claim to clean, brighten and freshen carpets. The instructions claim that consistent cleaning twice a month "is the key to cleaner, brighter, fresher carpets", but we can't substantiate this. We didn't notice anything different on the test carpet, but the cleaning solution smelled nice and fresh, and the carpet was left only slightly damp.
The Sonic Duo is also designed to clean stains from high-traffic carpet areas using a pre-treatment spray, a greater concentrate of solution and the special Scrub 'n' Stain pad. You'll still need to give the area a final vacuum after treatment. We didn't analyse how well it actually loosens dirt from deep down in the pile, but our staff member who tried it out at home did notice that it cleaned some dirty marks from the top of a woven mat.
The Shark Sonic Duo KD450NZ is an effective hard floor cleaner, with excellent cleaning results for common stains such as muddy footprints, red wine, tomato sauce and soy sauce. Although we can't fully verify its carpet-cleaning claims and ongoing ability to rejuvenate carpet, it did leave the surface smelling fresh, and our staff member did see evidence of some stain removal.
You'll need to get used to the various cleaning solutions and mop pads as you learn to use the Sonic Duo, however. And another downside is availability: you may have trouble sourcing this product on an ongoing basis, as it's mainly advertised on TV shopping networks.