eartaker is right, with leaving out the parts about what is suitable for drinking...
denatured alcohol is not rubbing alcohol...it is a solvent, and would be found with paints, or possibly cleaning supplies. it may remove paint, but should be safe for plastics. i notice mostly everyone uses it, so it must be relatively harmless to plastics, but is perfect for cutting oils and grease (for if you plan to paint something for instance) and if you've ever spray painted anything with any type of oil, wax or silicone, it will not stick, and will do what is know as "fisheye", where the paint sort of makes a circle around the spot where the contamination is. you wont hurt anything metal with any type of solvent or cleaner, just watch out for anything rubber or plastic...including air filters!
i've also read a good post about how to make a parts cleaner that is the next best thing to a sonic parts cleaner, if ya want the info on that, let me know.