The sea anchors found on merchant ship lifeboats carry a cone shaped dispenser designed to dispense vegetable or fish oil, neither of which is harmful. The amount held is approximately 1 gallon, the point being that it does not take a great quantity to acheive the desired effect. The response to this surprises me-I thought this information was common knowledge.
Marpol's opinion on this, being in a life/ship saving situation, can be left to another thread, let's stay on the topic of keeping positive buoyancy.
The Pardey's say, to Tartan's point, one must eliminate fore-reaching to create a "slick" to windward. They also seem to be big fans of the parachute sea anchor, cautioning against running too long before the wind.
Keep it comin'.