That is incorrect. Hair, toenails, and fingernails do not contain DNA, they are body waste products.
Actually your incorrect, as your no doubt aware, there are 3 layers to hair, toe, and finger nails, The root of each can deliver usable DNA, the Root of Hair and nails is connected to the blood stream and as such yields DNA of the owner, I do agree that the cuticle and hair shafts are useless, except for ID of hair color...
http://www.forensicmag.com/articles/2013/04/challenges-dna-testing-and-forensic-analysis-hair-samples