pretty darn pigmented!
I remember using these (or at least something equivalent) as a kid.  I bought these as a training aid for my toddler who is learning to brush her teeth on her own.  These tablets are the right dose for a large adult mouth - but for a child-size mouth, these tablets are overkill :)  I'd suggest either using a half tablet (if you can cut them, that is - they're small and not pre-scored for halving) or instructing your wee one to chomp on it twice, swish, and spit it out... otherwise the purple stains the mouth very thoroughly.  Purple tongue, purple drips, etc.  You really only need a little bit to identify where the plaque is.  They do the job as intended but I might not recommend this to messy kids who might spit or drip purple-stained saliva on everything in the nearby vicinity...
Rating: 4 stars