He mentions that they use some types of drugs that close/open ion channels to cause the growth patterns to change. I just googled and found that the human inner

He mentions that they use some types of drugs that close/open ion channels to cause the growth patterns to change. I just googled and found that the human inner ear alone has 300 types of ion channels. Is this technique just a matter of finding the combination of open/closed channels to get the desired effect? If so, the inner ear has a possible 2^300 combinations of open/closed doesn't it? This seems extremely difficult to do on anything that complicated. Or am I reading this wrong?