The Spaniards use the expression "Drink St Vincent's water" about people who talk too much or would like to take back things they have said in haste.
The expression goes back to St Vincent Ferrer, a Dominican priest who lived in the 15th century. The story is that once a woman came to him and complained bitterly that her husband was always short tempered and out of sorts and it was impossible to have an intelligent word with him. The woman asked the saint if he could suggest some way by which peace would come back to the household.
St Vincent told her, "Go to the Brother at the entrance of the monastery and ask him to give you some water from the monastery well. Take it along with you and as soon as your husband comes back in the evening, take a drink of this water and hold it in your mouth as long as you can. You must keep it in your mouth for a long time, otherwise it won't work.
The woman followed the advice. As soon as her husband came home, he was once again full of his usual ill humour and impatience. Immediately the woman took a gulp of the monastery water and kept it in her mouth a long time so that it would not lose its effectiveness.
Pretty soon her husband saw that he was talking to the air and stopped. The woman used this same miraculous remedy over and over again. After some time, her husband changed completely and even praised his wife's patience.
All smiles, the woman returned to St Vincent to thank him for the miraculous water. But he assured her with a smile, " It was not the water but you patiently holding your tongue that worked the miracle!"