Why would you do it with toothpaste??? That is why people with dreads get a bad rep for them being dirty. There is no need to use artificial products to make dreads. To tell you the truth it might have actually ruined your hair. I hate to say it but you will prolly have insects/bugs in your hair, because that is very unsanitary. I used to have a pair of dreads way back, and they were done by my two rastafari friends naturally.
But if they look good and you feel good. Righteous.