I don't know what it's like in the US, but in Canada, if you try to sell a safety device and put in your TOS that the device should not be guaranteed to provide

I don't know what it's like in the US, but in Canada, if you try to sell a safety device and put in your TOS that the device should not be guaranteed to provide any safety (even when used properly), the courts will throw out your TOS. You can't sell a safety product and then pretend it doesn't do anything.