The author's recipe does suggest doing exactly that:
Beef Tallow French Fries Adapted From “McMenu: Do-It-Yourself McDonald’s Restaurant Recipes” Yields two medium-sized orders of fries.
2 large russet potatoes
¼ cup white sugar
2 tablespoons white corn syrup (Karo)
1–2 cups hot water
6 cups Crisco shortening
¼ cup beef tallow
Salt to taste
1. Peel the potatoes and cut them into shoestrings. They should be about ¼ inch x ¼ inch in thickness and about 4 inches to 6 inches long.
2. In a large mixing bowl, combine the sugar, corn syrup, and hot water. Stir to dissolve the sugar. Place the potatoes into the bowl of the sugar-water and refrigerate for 30 minutes.
3. While they’re soaking, pack the shortening into a deep-fryer. If you don’t have a deep-fryer, any sauce pot or dutch oven will suffice as long as you have an appropriate thermometer. Heat on the highest setting until the shortening has liquefied and reads between 375° and 400° F.
4. Drain the potatoes then dump them into the fryer (be careful, it will be ferocious). Nudge them around to make sure they don’t stick to one another. After 1 to 1 ½ minutes, transfer the potatoes to a paper towel–lined plate. Let them cool 8 to 10 minutes in the refrigerator.
5. While they’re cooling, add the beef tallow to the hot shortening and bring temperature back to between 375° and 400° F.
6. Add the potatoes and deep-fry again for 5 to 7 minutes or until golden brown. Again, nudge lightly to keep them from becoming one mega-fry. Remove and place them in a large bowl, sprinkling generously with salt and tossing to mix the salt evenly. Serve hot and enjoy.