New research has uncovered a strong link between chemically sterilised dummies and food allergies.
Parents are being urged to think twice before using antiseptic solutions to clean baby pacifiers.
At 15 months old, Oakley Butler has ditched his dummy. But midwife mum Corinne says she always kept it clean.
"I washed them with soapy water and boiled them basically," she told Newshub.
"I'd carry some little wet wipes that I'd clean them with - don't want to put any chemicals in him that's for sure."
An Australian study of 700 babies found sterilising dummies with antiseptic could be compromising their immunity.
Professor Anne-Louise Ponsonby from the Florey Institute says the results are significant.
"Children who used a dummy with chemical sanitisers at six months of age had nearly four-fold high likelihood of food allergy."
What's unclear is why. Study authors say whether the chemicals in the antiseptic alter the bacteria in babies' mouths, or perhaps cause some leaching from the dummy is not known.
But researchers say parents shouldn't be discouraged from cleaning dummies as it's vital to keeping children safe.
The study found no increased risk of food allergy when dummies were boiled in water, rinsed under a tap, put in their parent's mouth or not washed at all.
And when children spit the dummy, parents have a few ways of dealing with it - from a full clean, to a quick brush-off.
"We need to be aware that there is dangerous bacteria in the environment and dangerous viruses," says Professor Franca Ronchese from the Malaghan Institute.
"By all means [we] want to keep our children clean, but sterile is not necessarily essential."
So clean is good, but you may want to avoid chemical sterilisers.