She shared the outcome with the group, admitting “I’m totally grossed out but have to share.”
“The fact I sleep under it has totally made me sick. I didn’t want to post but my sister Kirsty told me to, please be nice,” she said.
The photo revealed the filthy bath water after the bed sheets were removed.
Hundred of comments were left on the group, according to The Daily Star.
“Wow! I’ll have to strip mine now – eek,” one said.
“I’m cringing because I haven’t washed mine,” another said.
Many commenters praised Sara for sharing her clever hack with the group.
“Go girl! Bet you feel heaps better now, and will sleep more soundly.”
This article originally appeared on Better Homes & Gardens.