The actress posed next to the oversized latrine at Manchester's Trafford Centre for United Utilities campaign 'Think You Before You Flush', which aims to raise awareness of what can and can't be sent down the loo.
Ghadie, who has a 3-year-old daughter named Freya with ex-husband Matthew Smith, also called for wet wipe manufacturers to improve packaging labelling so consumers know not to flush them.
"You'd think it would be obvious to put toddler wipes in the bin, but when the packaging says 'flushable' it's no wonder people get confused," she said.
"You've got to bin these items because the last thing you want is a blockage and a flood."
One in every 530 homes in the North West floods every year because unsuitable items are flushed down the toilet, costing United Utilities £13 million.
"This year alone we have had to deal with 28,000 blockages across the North West and most of these are caused by sewer abuse," Tony Griffiths, wastewater network manager at United Utilities, revealed.
Ghadie is currently at the centre of a major Coronation Street storyline involving Maria falling in love with gay friend Marcus Dent (Charlie Condou).