Review (4/5): Hummingbird refills
Seems to be quite a good product. I have been using the Hummingbird flosser for about a year now and have noticed that the dentist spends less time cleaning my teeth. He has even given me a free mini-whitening!
One thing I learned is that the piece of floss being much shorter than normal floss means that I have to angle the flosser back and forth and run it up and down a few times. Normal floss bends around the tooth but the Hummingbird floss does not.