How was it too complex? You power on the Wii and point the remote to click the Netflix channel big and red right on your main screen assuming you put it there. From there click the search button to search or the arrows to move through the choices.
It's honestly one of the more user friendly options I've experienced for Netflix because the remote lets you point at what you want, compared to doing it on a smart TV, several mobile devices, a Wii and an Xbox.
Rather than spending money on another gadget I wonder if you'd be better off just walking him through it once or twice and then making him a little step by step reminder list? We used to do that with older relatives to help them remember how to turn on the computer to check email, etc.