For cotton and polyester: Scrape off large globs with a dull knife. Rub in glycerin and let sit until remaining sap has softened. Place garment stain side down on a towel and tap to loosen sap. Rinse. If stain persists, apply commercial stain remover appropriate for the fabric. Machine wash.
For washable silk and wool: Same as cotton and polyester, but take garment to a dry cleaner if stain remains after treating.