I saw that being done on that show, Show Dog Moms & Dads or something like that. He was pinching the dog's anus in a certain way and stuff was squirting out!
It was totally gross lol and some got on his shirt and even the camera man didn't want to get close. He said it smelled something terrible LMAO!! I think I will leave that part to the vet unless I knew someone experienced who showed me how to do it if it was absolutely necessary.