Turn the oven to its lowest heat setting.
Fill a baking pan with 1 inch of water.
Add a small amount of lemon juice until the water smells strongly of lemon.
Place the baking pan into the heated oven.
Leave the baking pan in the oven for an hour, checking periodically to ensure the water hasn't completely evaporated.
Remove the pan from the oven. At this point, the smell should be gone.