I was afraid of harming my snakes when i tried to pop them so i waited till they got a little bigger then i probed them, was still scared when i did that but it wasnt as bad as i orginally thought. They fought alot more from trying to get popped then probed in my experience.
But always make sure you know what your doing before u go willy nilly with a probe and popping, dont want to buy an expensive snake and make it sterile by screwing it up.