The best way to get rid of a soapy taste in your mouth is to taste something else that's stronger. Good options include coffee, sweet tasting things, and even mouthwash. But before you reach for the mouthwash or toothpaste, you should probably read on.
Why shouldn't you just brush your teeth?
Most of the time, brushing your teeth and using mouthwash will get rid of unwanted tastes in the mouth. Of course, if you've actually eaten soap, this is probably a great way to remove the soapy taste in your mouth. There is, however, another more serious reason for having a soapy taste in the mouth.
Ingesting too much sodium fluoride can be a common reason for a soapy taste in the mouth. It's used in toothpaste, mouthwashes, and even tap water. Too much sodium fluoride isn't good for you, and if you continue to have a soapy taste in your mouth, you should visit a doctor for further advice.