are you sure you didn't read grapefruit seed extract? grape seed extract and grapefruit seed extract are two different compounds with different actions, i believe the grapefruit seed extract is what you wanted.
you can try the garlic oil, many have success with that. also you might want to try some hydrogen peroxide drops into your ear. this is the quickest and most affective method of killing off pathogens in the ear canal in my opinion.