I don't have an answer for you. Nobody does. What I'm saying is that if you start doing something biting your tongue to get over a block, it can easily become a secondary behavior. Essentially, something that seemed to work for a time becomes a part your stuttering. For me, it's clearing my throat. I started doing it when I was younger because I felt like it helped me get over a block but also because, if I was on the phone, it let the other person know I was still there. And now it's almost involuntary. When I start to block, I clear my throat over and over again. You don't want to be 40 years old and biting your tongue every time you have a block.