Narrated Asma’ bint Abi Bakr:
A woman asked Allah’s Apostle, “O Allah’s Apostle! What should we do, if the blood of menses falls on our clothes?” Allah’s Apostle replied, “If the blood of menses falls on the garment of anyone of you, she must take hold of the blood spot, rub it, and wash it with water and then pray in (with it).”
It’s pretty simple. Most of us already know it, but there’s no harm in reminding.
The ease here is that the affected clothes can be used to pray in after cleaning. But Jewish women had to cut off the piece of cloth where blood of menses touched. So Alhamdulillah for Islam! :)