Dip a soft cloth into a small jar of mayonnaise. Use the cloth to scoop out just enough mayonnaise to cover the stained area.
Rub the mayonnaise into the stained area with the soft cloth using circular motions.
Leave the mayonnaise to sit on the leather for at least two hours.
Remove the dried up mayonnaise with a clean damp rag.
Remove the spray cap from a 4-oz. spray bottle and pour one-half cup white vinegar into the bottle.
Add 1 cup linseed oil to the spray bottle.
Replace the spray cap onto the bottle and shake it to thoroughly mix the ingredients.
Spray a light mist of the vinegar mixture on the leather and allow it to sit overnight.
Rub a polishing cloth on the leather using a circular motion. Continue this process until the leather develops a healthy shine.