If you need to induce vomiting, hydrogen peroxide is very good and works. I gave about 1TBSP per 10lbs of body weight, so for Jamie when I had to induce her vomiting I gave her 4TBSPs.

It works IMMEDIATELY so make sure you're in a safe area and stand away!

EDIT: I will add I had to induce her vomiting because she had eaten 2 1/2 of chocolate nut fudge and that was safe to induce vomiting for.