I use to be a licensed nail tech and found out a hidden secret from one of my customers, she would put vicks vapor rub on her feet with socks every night. Her feet were like a new born babies feet. The campher in the vicks is what does it. Try it, you'll be surprised.
I don't think the ingredients in ketchup are good moisturizers to relieve dry feet. The ketchup may irritate the skin and make the problem worse. Perhaps you should use proper foot care products such as lotion, cream, ointment, wax, etc.