I've done it to others and have had it done. In fact, I've had my toes stretched back to the point I could not move my feet at ALL! And yes, it makes it worse (or better!) 🙂 It ddrove me insane! Use a wide, soft thick material...I have used those things you put on glasses and around your neck so they don't fall off in sports etc. They sell many different kinds, but look for the soft cotton ones...OR, a wide ribbon that will not cut into the toes. And, there have been a few times where it tended to hurt but the tickling soon became far more powerful than any pain. But for me, it stretched the arch which is my kill zone...and when the foot is COMPLETELY restrained, the tickler can be MUCH MORE precise! Shudder!