This is a very common misconception.
Normal antifreeze contains ethylene glycol, which is poisonous. RV antifreeze contains propylene glycol (not poisonous). Neither stabilizes wood well, and using ethylene glycol can be very dangerous depending on what the intended use is.
Green wood is stabilized by soaking it in polyethylene glycol (PEG). This displaces the water in the wood cells and prevents drying cracks as the wood dries out. That's it.
You can buy PEG 1000 at some of the bigger woodworking supply places, but I cant see a use for it in bow making.
Great for wood turners though if you want a piece that will always feel waxy