So, are you saying it is a WASTE to practice the lifts? Look at the span of a person's athletic career (competitive or not). A few weeks or even a few months is not a lot of time in comparison. It is time well spent.
True, if you improve your overall strength your power clean would increase, but who said you couldn't practice the technique AND get stronger with the basic exercises? If he would like a bigger clean/power clean, he should learn the movements and continue improving strength in squats, deads, good mornings, etc (like you said).
If he doesn't work on the technique, he will end up muscling the weight up or doing many of the other possible errors that would make him prone to injury. He doesn't need to master the technique to benefit, all he can do is develop sound technique.
I have taught myself pretty well without a traditional coach, although I routinely post my vids on OL forums for critiques and am always reviewing my vids and studying others. It can be done.