i'm not sure if this is the best place to ask this question, if not please let me know a better place. I just purchased a very cheap 300 gallon water tank. It was cheap due to the fact that they stored Canola oil in it, and didn't clean it. They recommended a de-greaser along with a high powered water sprayer. Before I try it, I wanted to see if anyone had any advice on cleaning it, if a de-greaser is the best route, how much I need to use, or any other advice.
Also, my mom said if I don't get all the Canola oil out, it never spoils and it wouldn't kill us to drink if there was a disaster and we HAD to drink it to survive. Is this true? Thanks in advance.
Edit: We will be storing water in it as emergency water, and it is plastic, i'll attach a picture.