Usually not needed. Douching can be used to treat some gynecologic problems usually, however, it is not necessary and can be irritating and counterproductive. An alternative is to moisten a finger with soap and water and insert vaginally while showering.
Yes and no safe way. With rare exceptions, douching is a bad idea. The process tends to kill more of the good bacteria and less of the bad bacteria which tends to make you worse. A healthy vagina is moist with little to no discharge and no unpleasant odor. If you even think you need to douche, you need to visit your doctor.