"Who knew? I've been doing it wrong forever!" he captioned the video.
The video got hundreds of comments, with plenty of people amazed that they too had been "doing it wrong".
"Looks like I have been doing it wrong; wonder why my dishes are not clean," one person wrote, while another added: "What, all my life I've been living in a lie."
But not so fast.
As the views clocked up, more comments came in correcting the supposed hack and accusing Jeffreys' video of starting an "intense argument".
"That's totally wrong, you had it right the first time," one person commented.
Another commenter even went to the source to check and clarified: "After seeing this I had to check the manual. Unfortunately you're wrong. It's for the pre-clean programme."
With all that confusion, news.com.au thought it was best to consult an expert.
Appliances Online's Colin Jones said that while putting a tablet in the wrong slot probably won't damage your dishwasher, neither will it clean your dishes properly.
"While the placement of the tablet won't necessarily have an impact on your dishwasher, it could impact the cleaning results," he said.
"Older dishwashers, around five years and over, weren't designed for three-in-one tablets. In older dishwashing machines, there tended to be three sections for dispensing, which is highlighted in this dishwasher in the video, including a smaller vented pre-wash compartment, the compartment for the main wash and a rinse aid compartment.
"The smaller section in this dishwasher in the video is a pre-wash compartment."
Jeffreys has since responded to the confusion and admitted he got it wrong. "I know, I realised about 300,000 views ago. It's gone crackers," he wrote.
However, plenty of people claimed it probably didn't matter and said they had been told not to bother with placing the tablet in the slot at all.
"Our plumber neighbour said it's always better in the bottom ... our stuff is always clean and sparkling," one person wrote.
"I mean ... it probably doesn't matter where you put it but that bigger slot is obviously correct," another comment read.
For an optimal clean, Jones told news.com.au he recommended two options.
"In current dishwasher models on the market and sold in Australia, you either place or dispense the three-in-one tablet at the bottom of the machine and it will break down each section (pre wash, main wash and rinse aid) when needed, or your machine may have a tablet button on your control panel, to let your machine know you are using a tablet rather than powder and it will dispense the tablet at the correct time for the cycle."
