Proper old school advertising. Dramatise the benefit in a way that stops the reader turning the page, make it especially impactful for the target audience (parents with small kids), don't insult the reader's intelligence, tell a story quickly and colloquially as though you were talking face to face, give the reader clear reasons to believe you, and end the copy with a gag that makes the reader feel you're repaying their investment in reading an ad. Can't remember the last time I saw one that even came close.
The shampoo ad bit reminds me of the classic ad for child roller skates (no pics allowed here, but nicely broken down by Lewis Folkard below):
https://lewisfolkard.co.uk/ad-breakdown-fisher-prices-anti-slip-roller-skates/
Nice story, I hadn't seen that before!
Proper old school advertising. Dramatise the benefit in a way that stops the reader turning the page, make it especially impactful for the target audience (parents with small kids), don't insult the reader's intelligence, tell a story quickly and colloquially as though you were talking face to face, give the reader clear reasons to believe you, and end the copy with a gag that makes the reader feel you're repaying their investment in reading an ad. Can't remember the last time I saw one that even came close.