Moisten a cloth with hot water and place it over the unwanted fish glue.
Cover the cloth with a piece of plastic wrap to keep it from drying out. Secure the materials to the furniture with string, if necessary, to hold them in position. Keep the affected area completely covered for at least four hours.
Remove the plastic wrap, cloth and, if necessary, string. Dip a toothbrush in warm water and gently scrub the loosened fish glue. Wipe up any adhesive that comes away from the furniture with a damp cloth.
Repeat as needed until the fish glue is gone.
Soak a cloth with distilled white vinegar, then rub the furniture with small, circular motions to remove any fish-glue residue.