Vinegar is an ingredient in many homemade, natural cleaners, and there is a reason for it. It is a natural disinfectant. However, for washing organic leafy greens, it isn’t necessary. Good old H2O and some handwashing action will do the trick. However, if the kale bunches you buy aren’t organic it is possible they have been sprayed with pesticides. There is acetic acid in vinegar and according to some experts, this could help dissolve those chemicals.