This means:
“You supposedly only need one dishwasher tablet to clean a dirty oven and make it look almost new again.”
Breakdown
“All you need is a dishwasher tablet!” = claims that a single dishwasher detergent tablet is enough for the cleaning job.
“The oven will be like new again” = promises a dramatic cleaning result, removing grease, grime, or baked-on residue.
The headline implies the method is cheap, simple, and effortless.
Tone
This is a household-cleaning clickbait headline. Phrases like “all you need” and “like new again” exaggerate how easy and effective the trick is.
A simpler version:
“A dishwasher tablet may help remove stubborn grease and grime from your oven.”
One caution: dishwasher tablets are formulated for dishwashers, not necessarily oven interiors. Don’t use one in an oven unless the oven manufacturer and the product instructions indicate that it’s safe, and avoid getting detergent on heating elements, electrical components, or surfaces that could be damaged.
