Outdoor limestone ... water using a garden hose or a bucket. Make sure no soap residue is left behind, as it can leave streaks or attract more dirt over time. 4. Spot Clean Stubborn Stains For ...

"OMG, I am so glad you managed to get these stains off!!!" said another Instagram user. "Thank you for sharing! We have some limestone at our house. Will try this for cleaning!" wrote one viewer.

the facade is restored, thanks to a process that soaks the limestone under low pressure for six hours. “Limestone, if you soak it with enough water, will release what it has absorbed,” Pagac said.