First, grate the russet potatoes. Transfer to a bowl, and sprinkle half the salt over top. Using your hands or a fork, disperse the salt evenly through the grated potatoes. Allow to sit for 10 minutes.
Then using a clean thin cloth or a nut milk bag, drain as much liquid out of the potatoes as possible. Dispose of the liquid, and transfer the potatoes back into the bowl. Add the remaining salt, nutritional yeast and garlic powder.
Coat the waffle iron with spray oil or using a barbecue brush, liberally add oil to the waffle iron grates to avoid any sticking. Transfer the grated potato mixture onto the waffle iron until slightly over-stuffed and close. If your waffle iron has a heat setting, turn it to medium-high.
Allow to cook for five minutes before you begin intermittently checking to avoid burning. The potatoes are ready when they are crispy on top and golden brown. Unplug and safely remove from the waffle iron using a silicone spatula. Serve with ketchup as desired.