I used Simple Green until I saw a response from the makers of Simple Green, posted on a forum (perhaps this one), that said to NOT soak saw blades in Simple Green.
I also saw something that said the FAA did not allow Simple Green to be used on airplanes, because if it seeped into a crack or joint, it could corrode the structure (not a good thing to do to airplanes).
I found it interesting that "Simple Green Extreme" had been approved by the FAA... apparently the "Extreme" version is less corrosive. After looking for a long time, I finally found the Extreme version available at Sams club in gallon jugs of concentrate. That is probably more than a lifetime supply, but it works good.