Hello, thanks for your question today! I am Dr. Drew, and I am a licensed veterinarian. I'll be happy to help you in any way I can.
salt water is never a recommended method to induce vomiting,
as it can lead to dangerously high levels of salt in the blood, known as hypernatremia.
a preferable home method is 3% hydrogen peroxide,
1mL per pound of body weight (2mL per kg), up to a maximum of 45 mL for dogs larger than 45lbs/20kg.
ideally, in the veterinary clinic an injection of Apomorphine is used,
but if veterinary care is not available, peroxide is often the only alternative.