MaDMaXX, do you worry about lead dust from primers? If not, I wouldn't worry about "toxic chemicals" in your cleaning solvent.
Copper iteslf can cause heavy metal toxicity. Selenium is an essential trace element but deadly in higher quantities.
If you want to talk about the danger of mutagenic compounds we can do that, or if you want to talk about low dose toxicity substances (such as Uranium or Plutonium) we can talk abou that.
But just saying "toxic chemicals" is like saying "wet water."
Bottom line, ANY of the cleaning solvents listed can and will kill you in a sufficient does. ALL of them are perfectly safe when used as directed.
Machine guns are awesome until you have to carry one.