"There are all these amazing old Victorian toilets, like really traditional, floral numbers with pearl patterns, and I just thought, 'wow, that's amazing, why is nobody doing that?' It was a little bit of a light-bulb moment where I was like, 'well, I'm going to do that'."
She was "dabbling" in printed ceramics at the time, working on plates and tiles, which gave her an idea of how to go about making a toilet, she said.
The eye-catching designs are inspired by the natural world, as well as art deco and art nouveau styles, with an abstract twist.
"It's my own prints so they are, to start off with, a little bit out-there compared to the more traditional interior style patterns you get - there's definitely room for expansion on that."
The loos were more suited to commercial ventures than a traditional home, she admitted, but she has dreams they will become a household feature.
"In saying that, I do think it's much more of a commercial product for bars, hotels, restaurants, that kind of thing."
She is currently in discussions with a nightclub in Glasgow to kit out its loos in her unique designs.
However, the funky thrones don't come cheap.
"They are quite expensive, I know that myself, but people do spend a lot of money on their interiors as I've found out, so it is something that people are willing to spend money on."
The production cost was also relatively expensive, she said, with materials becoming more difficult to find in a niche market.
Ms Finnigan, who married her Scottish husband Ralph McKenzie six months ago, also makes plates, cups and saucers, mugs, tiles and duck-shaped toilet brush holders.
While some of her friends were a bit sceptical of her plans for toilet domination at the start, most were supportive, she said.
"Bathrooms are so neglected when it comes to colour and patterns, so there was nothing going to stop me, I was going to do it."
Earlier this year, Ms Finnigan won a 2500 pound cash award from Start for 6, a Scottish start-up and investment programme for creative industry entrepreneurs, for her designer toilets.
A Massey University textiles graduate, she moved to Glasgow seven years ago after winning a scholarship to complete her Masters at Glasgow College of Art.