It is a likely possibility that your little Yorkie may have a yeast infection, from what you are describing about his feet smelling like Fritos.
Mercola.com has a great tutorial video about yeast infection in dogs, how to detect if it is yeast, and also how to treat it, if it is a yeast infection. They have instructions for making a simple dip from white vinegar and hydrogen peroxide, that will disinfect the dog, and kill the yeast .
You just soak the dogs feet in it, and pour some over the rest of his body, being sure to not get any in his face and eyes.
Here is the link to the YouTube video' and hopefully , it will be helpful to you.