When you teach a thing - don't teach "what shouldn't be done" mixed in with "what should be done". It's a recipe for confusion. Stay on track with the one mode: you're teaching a thing. Teach the thing first.

Teach me the right things.

Then, if there are safety issues with other common methods, follow up AFTER with a "here are some ways that people try to do this - but you absolutely shouldn't do. If you see these things, they are wrong and dangerous. Avoid these ones."