I love cracking any joint I can… Knees, hip, back, knuckles, toes, etc..etc

My girlfriend told me about a time when she was receiving a pedicure in which they massage your feet beforehand. The person performing the pedicure somehow cracked a bunch of joints in her foot...all simultaneously like a gattling gun. She described how he wrapped his fingers of both hands around the top side of her foot and pressed his thumbs somewhere in the area near the base of her toes. He this either pressed or pulled somehow as if trying to fold the foot in half on itself and she said multiple joints had cracked at once.... joints that she had never felt cracked before. At once I was intrigued... not only to try on myself, but I want to learn so I can reproduce it for her. Has anyone else experienced something like this and know how to reproduce it?

Thanks!!