One of the key ways we teach writing to English Language Learners at our school is by using materials from The WRITE Institute. They have great stuff.
One of their units is on the persuasive essay. A review of different advertising techniques is included in the lessons.
Coco’s Adversmarts would be a nice supplemental online activity to that topic. Students have to create a website using various advertising techniques to attract children. It’s designed to help students see these sites are really just prolonged commercials.
It’s very accessible to all levels of English Language Learners, with text, audio support, and multiple images.