What some folks don't realize is that most pine cleaners are only 5% pine oil. Most of the rest of that bottle is just water. I don't like paying for water, so I get the concentrated stuff. Pine-o-Pine is sold at my local hispanic grocery, and it's 30% pine oil:
The bottle isn't very big, but when you only have to use it by the half-teaspoon it lasts a long time. One of these typically lasts me a year or more. Always read the label before you buy. There are some pine cleaners *coughSuperPinecough* that misleadingly label themselves as "90% pure pine oil and surfactants", to make you believe they have more pine oil in them than they do.