Learning to wipe should begin as soon as the child learns to use the toilet. At first you will do the dirty work, but your child should do the second wipe, as he learns the motion and becomes better able to reach his hind quarters. Some children even do best getting off the toilet and squatting down so their cheeks easily spread to an open target. Some children like to do a spot check in the mirror. (Back to the full length mirror, bend over, and look in the mirror between the legs.)
I just googled it and you're doing it backwards. You don't go second you wipe first then they wipe second to check your work and that way they practice the motion.
