You might try limiting your objections to what should be taught in science class. For instance, you might emphasize that any theories taught in science class should identify the criteria that could falsify the theory - if you do that be sure to know what criteria would falsify any scientific theories you defend.

the OPPOSITE of science, and tantamount to mentally abusing the children who learn about it, by PRETENDING to be a science. Creation science is nothing more than Christian religious pretentiousness.

I wound up unable to go, though I did spend considerable time formulating remarks basically pointing out that creation science is not science and questioning why one would ask public school science teachers to teach religion.

and the people best able to teach religion to the children are the churches and their parents.

Arguments that creationism isn't science because the results are not able to be reproduced in a lab (while evolution has been on a small scale) are going to fall on mostly deaf ears.

Telling them that their religious horseshit will be taught wrong by the schools might not.

Why would a bunch of people who don't trust the gummint to perform its most basic functions be so eager to charge public schools with teaching their religious beliefs (which they care a lot more about than biology)?

I think the most compelling reasons creation science and its variants are not science are basic logic... no theory that appeals to a supernatural cause can be a scientific theory, pretty much by definition - scientific explanations are intrinsically naturalistic. You're breaking the rules of the "game" if you appeal to anything else.

My favorite summary of the situation is probably this: