If he wants to throw he HAS to learn to center.
Honestly I don't think it's that hard but...
In the community studio I am working at I have helped a few people, but in different ways.
One guy would sit there and just try and center for days on end. Nothing else. I finally told him 'Just do it' time to pull, you need to finish one piece and work through all the steps. If you only try to center all you will ever have is a lump of clay. BORING=quits. If you jump in both feet first you will have a wobbly cup. What's better? I really well centered lump of soggy clay or a wobbly cup?
A wobbly cup. Why? Because you have experienced throwing from start to finish and you now have points to improve upon. OR, you could have a really nice lump of clay. Now he is throwing some pretty nice large 'bowls' (more shaped cylinders but...). The point is he kept going and now loves it.
I think that is what Marcia meant. It is better to have a bad center, keep going and learn to pull, to clean lip, etc... and get through the entire process once. THEN do it again BETTER. Then again, etc.. Spending 5 hours centering is not fun. Spending 30 minutes working through the process is. That leaves 4 1/2 hours to try again, and again, seeing improvement, building muscle memory, achieving something.
Other people had sticking points. Too much mositure, too dry and sticking hands pulling clay out of round. Foot propped up on pedal throwing off balance, etc...
Kept using wrong hand positions until I corrected them 20 times in 10 minutes, etc..
I've been at this for 2 years and have TONS to learn but my advice teaching him is this:
1:Cylinders. They are easier. (with grain of salt, a really tall cylinder is harder than a really small bowl). But a cylinder can be turned into a bowl, not vice-versa. (still best to throw bowl as a bowl)
2: Show him the basics, let him work. Watch him closely and catch his mistakes early. Be patient but diligent. Don't let him develop bad technique, that turns into bad throwing, frustration and giving up. Better to be frustrated for the first 3 hours, then the first 3 days.
3: wedge up 5-10 balls of clay (not one). have him throw one, when it fails scrape it away and start over. Everyone wants to keep first throw, yet it's probably not worth it. Install early that it's OK to toss a bad piece and try again. 1 makes 2 better, 2 makes 3 better...
3 days is plenty of time to learn (basics) imo, but that depends on time. 30 minutes a day, NO. 3 hours a day, YES. I guess that depends on student/instructor too. I have seen instructors ramble on for hours telling students how, then walk away when students try. Students get frustrated and I jump in and say... let me help you as you do it... and they end up with a thrown item on their first ball of clay (even if horribly rough).
Throwing is not hard if someone sits with you one on one and catches/fixes your mistakes.
It is IMPOSSIBLE if the teacher walks away and leaves you to your own vices.
I have also found strict weights don't matter. Clay is a loose subject. For some 1 pound might be easiest. My hands are fairly large and one pound of clay is TOUGH. My fingers get all bound up on each other. 2 pounds is much easier to handle, I have room to breathe yet it's not too much weight/size, etc... 4 pounds is probably just too much for a beginner though.
Be loose, but don't let bad habits develop, but don't be over bearing. Sometimes it takes mistakes to realize a bad habit needs correcting. Make it fun first and foremost, if he still doesn't like it he never will. If it's fun and he sees it is possible then he can determine how serious he wants to get.
The basics of clay are easy with a little help and fun, almost anyone can teach that. To be really good depends on willpower and nobody can force that on anyone.