I gave this product a terrible review initially, because it came with no instructions, and I couldn't figure out how to use it effectively.
However, after searching YouTube for instructional videos on "How to use a Handheld Drain Auger", I managed to get the device to work properly. So the device itself is excellent. But the lack of instructions is a real issue.
It immediately cleared the blockage which more than 10 Litres (I kid you not!!) of Hydrochloric and Sulphuric Acid (the super-strong dangerous stuff plumbers use that dissolves anything it contacts), had been unable to clear. It took no more than 10 minutes. I wish I'd found the instructional videos before I wasted so much money on drain unblocking acids.
Anyway, for those who have no idea how to use the Auger and want some instructions, I'll explain how it worked for me:
1) Turn the screw on the end of the auger and pull out about 2 or so feet of cable, then tighten the screw again so the cable can't move in or out of the auger.
2) Put the springy head of the auger into the drain opening and start turning the auger (holding the 'gun' bit with one hand and rotating with the other).
3) While turning the cable, begin to SLOWLY feed/push it down into the drain. Try to keep the cable upright above the drain if you can. It's important to keep it turning while doing this so the cable begins to coil down into the drain by itself.
4) When the cable has mostly disappeared down the drain, stop turning/feeding it. Untighten the screw on the end and pull out another 2+ feet of cable, then tighten the screw again.
5) Repeat stages 2-4 until you feel some resistance - which probably means you've reached the blockage (though you may have already bashed/broken the blockage aside without even realising it).
6) As I was feeding the cable in, I made a habit of pausing for a minute and vigorously plunging up to about 12inches of the cable in and out of the pipe to try to scrape and dislodge any gunge that might be sticking to the sides of the pipes as I was going down.
7) If you have a complete blockage that you feel you've snagged, you can now pull the coiled wire back out of the drains (slowly feeding it back into the auger) and hopefully dragging the blockage out with you.
8) If you don't have a complete blockage, you might find it helpful, after a while, to turn on the hot water a little and repeat the plunging so that anything that is being dislodged as you feed the wire down is washed away down the drain.
9) As a final tip, I'd recommend running the hot tap once the blockage is cleared and further plunging the cable as you slowly feed it back into the auger. This will help clean the cable and wash off any smelly gunge that's been stuck to the cable on the way in.
Hope this helps. Good luck!