A solid knowledge of English grammar and structures may not be necessary for a child, but we all agree it is often an immense help to a thinking, adult student. The adult learner's ability to analyse and incorporate language patterns is a great advantage we must use while helping them improve. Instilling an awareness of pronunciation patterns is just giving them another skill, and it will be a process.
Pronunciation awareness, like an awareness of grammar, is a helpful, transferable body of knowledge for an adult which can only benefit an analyst and user of a spoken language. They will be scared at first since grammar is often taught while pronunciation is taken for granted in elementary schools round the world. You may be their first teacher.
But there is a benefit in not knowing everything about it: your discoveries in this area will occur at the same time as theirs. It is just like when you started teaching new materials: at the beginning you didn't feel like you knew it all, but the classes still learned. And if you really enjoy languages it provides years full of discovery.
You must expect loads of suprises as you encourage students to trust their ears not your instructions. They will find flaws or "characteristics" in your accent which you may be unaware of. This will fill them with that revolutionary pleasure that comes from truely learning something... and besting the teacher. Let them soak it up. But when they start making those observations remember you played a small part. And the students next months will start making them even faster.