I see no point at all in using WD-40, due to the expense and the fact that the extra expense comes from adding a lubricant to the kerosene that is almost always too light. As noted, Simple Green is not "green" when mixed with the grime on your chain, and it absolutely should not be put down a storm drain. Even biodegradeable chemicals can add to the problem of algae blooms. I prefer odorless mineral spirits, and as noted they are recycled. I leave the original lubricant on the chain, as many credible sources have said that is very effective.