Oral-B has been trying to convert Israelis to electric toothbrushes for years. Despite its best efforts, however, just 20% of adults have switched from manual brushes – one of the lowest rates in the developed world.

Dentist endorsement and millions spent on advertising have had little effect. The high initial cost and a sense that electric toothbrushes are only for people with serious dental issues have created an impenetrable barrier.

With the launch of the new Oral-B Genius brush, with its position detection technology, we had a unique opportunity to change the conversation.

Our insight was that there was one day of the year when only 100% clean was good enough: Yom Kippur.

It’s the holiest day of the year and Jewish people repent for their sins and fast for 25 hours. The country shuts down – no traffic, no media, no eating or drinking.

If you eat anything – even the smallest morsel of food – during that period, you are destined to an early death, according to Jewish law. It’s, therefore, no wonder that 70% of Israelis observe the fast!

A mouth that’s anything less than 100% clean could mean you accidentally swallow some of the food particles lodged between your teeth.

We needed a new brand advocate. If consumers wouldn’t listen to the person who kept their teeth clean, then maybe they would listen to a higher authority…

Our idea: Even the best manual brushing isn’t good enough for God.

We would hijack the holiest day of the year with a "100% clean teeth" message.

We would remind Israelis that the many tiny food particles in a less-than-perfectly clean mouth could be accidentally swallowed – leading to eternal damnation.

First, we would need to make sure that it wasn’t just Oral-B saying this. We needed backing from Israel’s religious leaders.

Second, we would amplify the importance of their advice, using media to drive our calls to action.

Finally, we would provide consumers with an easy one-click solution, letting them move seamlessly from message to purchase via Oral-B’s e-commerce partners.

Because much of our target audience wasn’t religious most of the year, we needed to make the message humorous. We would recruit some of Israel’s best comedians and get them to create a catchphrase that could become part of popular culture.

It would be a message from God.

We conducted a live side-by-side demo, pitting a manual effort against Oral-B to prove our 100% claim. We showed the results – certified by an eminent dentist – to Israel’s highest rabbinical authority, securing a religious decree that only electric brushing could save fasters from sin.

This demo became the centrepiece for a Print and OOH campaign in the run-up to Yom Kippur, showcasing the rabbinical recommendation to use Oral-B's electric brushes. Online we took over all content relating to fasting.

The heart of our campaign was a branded content video starring cast members from Israel’s leading comedy show, who brought to life the consequences of accidental food crumb swallowing during a fast. They created the catchphrase “You’re Out” to identify the fools who failed to use electric toothbrushes.

All content was directly linked to our e-commerce partners where super-fast delivery ensured the brush arrived before the fast began.

Our content became an instant hit with 400,000 views – index 122 versus Oral-B's most successful video before this.

The phrase "You're Out!" became a national catchphrase.

Our media efforts reached more than half the people who were fasting on Yom Kippur.

And we resurrected sales of Oral-B brushes to record-breaking levels. God’s recommendation ensured that Yom Kippur sales were 10% higher than those of Black Friday, Chinese Bachelor’s Day (more commonly known as 11/11) and Cyber Monday COMBINED.

• Oral-B Genius (the brush featured in our communications) indexed 187 vs. previous period

• All Oral-B electric brushes unit sales indexed 140 vs. previous period

• Total Oral-B sales (including manual brushes, floss and toothpaste) indexed 117

The success of our insight and strategy now means that a similar approach will be applied to the six other fasting days in the Jewish calendar.