Yes. It demolishes your forearms! When I was doing it, I wrapped the towel over the one place and held my hands on the same piece of towel, in effect, as close together as possible. Probably even harder on the grip than holding a towel in each hand or and end of the towel in each hand, or not?
That was about a year and a half ago though, so I've no idea how many I could do now. Back then it was about 5, but I've improved out of sight since...