Vasaline for style

A friend just called me and said her son (16) insists on using Vasaline on his hair for a greesed look. He says it's because it's cheep. She was wondering if there was reason for concern? I guess I'm not really sure what particular side effects to be concerned about except how difficult it is to get out. I doubt if this kid really cares if his hair is "choked" or not. Does anyone know of any specific side effects? Also, does anyone know of another "cheep" alternative?