Their latest collection, which started in August, is up to $1975 — with every cent going towards their Christmas spending.
The mum-of-three admits there are some downsides to the system.
"Of course it's annoying if I need milk and only have a $10 note, as all the change goes into the kitty so milk turns out to be expensive," she said.
"I try to pick up other items at the same time, or I end up with $10 milk."
Kellock said the easiest way to save was to go to the bank and get a stash of coin bags to safely put the money away.
"They are easy to keep an eye on and when the bag holds its amount, it's straight into the safe," she said.
"I would do this again and again — we haven't actually stopped in six years.
"I spent one $5 note once and had an attack of the guilts."
New South Wales woman Skye Kelly saved $1000 in the lead up to Christmas by saving her $5 notes.
"It adds up quickly if you don't count it all the time," she said.
"When I first started I counted it every month or two and it wasn't that much — but then I stopped counting it at all.
"Then when I wanted to go Christmas shopping, I thought I would see how much I had, and I had $1000 sitting there.
"It's easy as well — I didn't miss the money and I never thought about it.
"I just put it out of my mind so I wasn't tempted."
Queensland newlywed Danielle Kampe even used the popular savings method to pay for the bulk of her wedding.
"Basically we had seven months from when we got engaged to when we got married, and we figured it was one of those things we were only going to do it once, it had to be right.
"So any gold coins or notes under $10 were saved in good old coffee jars.
"We had two coffee jars filled by the end of it and it was about $3,000 that we could put towards costs by the end."