So, how do we get this crap out of the science classes?

In short, you can't. It is down to luck.

In longer form, you must vote for people who use believe will cut it out, even if that means voting for other policies that you really don't like: remember they are the ones who decide what is packaged with what.

Now suppose one thing is to insist on fully qualified science teachers from properly accredited universities, etc. That may cost more. So maybe solving the schools problem means higher taxes. Do you reckon people would vote for it? I don't.

Or suppose a party in favour of it has immigration policies you can't stand? What then?

Luck, I am afraid, may be all there is.