Polish, I am going with choice #4. Let it BURN.
Then I would get a custom tank of 7x3x3.
I would start buy flipping the box upside down and start a fire at the bottom corner base. After the starter corner starts to burn, stand back and enjoy it.
When the fire engulfs that box, catches to the top of (bottom of wooden tank) your project, sit back and you will get big fire for a hopefully a few minutes.
After that it usually dies down to a measly fire.
Unless you stack much more to burn around/on top of it.
I was going to burn something tonight but there's a chance of rain.