Although it is tempting to wash spaghetti stains in hot water, cold will work better, since heat will set the stains. Saturate the stain in dry cleaning solvent, and launder. If the stain is not completely gone, do not place item in the dryer.
You could also try placing the stained item in the sink with cold water dripping on the stain. Leave overnight, with the drips falling directly on the stain. This should loosen the stain.
