Add the 14 cups of cold water and 2 1/4 tablespoons of kosher salt to your slow cooker. Mix to dissolve the salt, then taste. The water should have the flavor of salt, but be sure it is not salty. Add another 1/4 tablespoon of salt only if needed.
Drain the tripe and pig’s feet and add to the slow cooker. Add the white onion and all the peeled garlic cloves to the pot.
Place the lid on the slow cooker and set the time for 8 hours. After cooking for 8 hours, take a piece of the tripe out and use a butter knife to cut it. If the tripe is gritty and hard to cut, the menudo may need about another hour. The tripe is done when it is tender and easily sliced. You can also taste it at this point to be sure it is tender.
In the last 15 minutes or so of the menudo cooking, pour the cans of hominy and their liquid into a small pot. Place the pot on the stove and bring to a boil. Simmer for 3-4 minutes.
Drain the hominy and add to the slow cooker. Switch the slow cooker to high and once it comes back to a boil the menudo is ready. Turn the slow cooker off or switch to warm.
Taste the menudo for seasoning and add more salt if needed.