It can be quite amazing what contaminates are floating around your house, and no matter how sterile the envrionement, something will become part of your rod it seems.
For instance, I have always kept my rods while curing in a pretty enclosed space so as not to attract any unwanted hairs, bugs, etc, never thinking what else was wanting to be part of my rod.
Next morning, theirs my stupid cat, curled up on the floor, nicely attached to my rod. Silly beast knocked it over and out of its protective envrionment, and decided to sleep on it, guess he thought he was protecting it.
for about a month, he walked around with a perfectly straight bair spot, where I had to cut the hair to remove him from my rod.