Those guys are just blowing smoke.....They do not want you, to do the work, for fear of being caught.
Look up antifreeze with the EPA......only restriction...do not put into septic tank. And the new antifreeze .....food grade ingredients.

IronPirate....the Big scrap yard in my location take all the plastic, rubber, oil, tranny fluid, gear oil, etc.....and use it to feed the shredder. I call it GKW.