Hi there!

 Last night I tried to make an all natural deodorant by mixing together the following ingredients. I left them overnight in a small plastic cup and when I woke up this morning the solution had ate through the plastic. Would love to get some help figuring out what caused such a crazy reaction . I should mention I am not a definitely not a chemist so I apologize in advanced if this questions seems silly. I have a feeling it might be something with the salt because it sunk to the bottom and thats where the holes in the cup were but again I have no idea.

• Magnesium Oil (I believe its magnesium chloride + water) 25g
• Colloidal silver, 2.3 grams
• Sea salt 1.4 grams
• Plus 15g witch hazel, 30g aloe vera gel, 10g vodka, 5g tea tree oil, 3g fragrance oil, 1/2 gram grapeseed extract

Thanks so much for your help!

My guess is the tea tree oil. 

That would be my guess too.
You could try each of the ingredients separately.