I use buttermilk but I have fried it 100 times with nothing but seasoned flour.
I put my flour in a gal zip lok bag and taste it, then start putting the cube steak in the flour bag. Shake it up and fry in hot grease.
I always lay mine out the day before, rinse it really good, squeeze it out then marinade it a little low sodium dales or watered down moores.
Only flip it once with a fork


Everything woke turns to shucks