"ch" sounds nothing like "k" in German. (Neither the "ich" nor the "ach" form).

You could claim it if you'd speak Bavarian (Chiemsee starts with a "k", for "Chemie" people are diveded if it's "kehmee" or "shehmee").

So don't use weirdly constructed things as names with your own pronunciation instruction. That's a tragedeigh.

I think it is somewhat ironic that you try to make a point that Chemie is an exception, when it is exactly the sort of example the claim is made from.

Ich and Chemie are pretty similarly pronounced (some people say either with a harder k sound, ik, "kehmee"). Chemie also derives from the Greek χύμεία, so it contains the Chi to make the comparison.

A similar case can also be made for Jesus Christus, I certainly think Christus' pronunciation starts like crust.

And hey, if you derive the Greek root for it, you get Χριστός, which starts with Chi again.

I think a better case can be made just arguing against mixing alphabets like this.