I have done this to my Allstate. It has rear brakes that activate by pedalling backwards. Anyway, I found this technique to be so premium, that I had to share it.
I used to have to stand up on my back brakes, and still could no way lock it up. I'd deglaze, and that'd last a few times, before I was right back to square one again.
I did this, and for almost a year now, I have been able to lock my rear tire up, while I'm sitting down, and haven't had to open it back up once.