When you started by saying "take it down to the metal" my stomach dropped lol. This is me 100% being lazy, but I think im going to stick to just scraping it all and washing it well. But 100% should have done insides first, just wasnt thinking/was excited to fix the outside. The spraying it each time with canola i will be doing on the inside.
One thing Im not quite clear/sure on is the exterior with canola oil-coat the whole thing? Reason I ask is because the vertical end farthest from the box will likely not get hot enough to have it cure properly and will be "sticky" whereas the firebox will be burning up.
The gator wheel works pretty fast and won't get the metal hot enough to mess with the paint like a grinder or flap wheel. If you don't clean it down bare metal the seasoning will just stick to what is stuck to the metal and then stuff will build up and over time get a thick coating of yuck.....Sorry there isn't a way to properly season a dirty piece of metal. But like I said I'm pretty particular with the inside of my cookers....
Oh and you only have to do the inside (only) with oil once. When I say wipe down between uses its just with a damp rag (since its warm it dries any moisture right out). You don't need to do oil every time. Just when you re-season which should be for a long time if you keep it clean. The out side is paint and I only wipe down spots of rust with oil when they show up on the outside......
For the vertical just put a metal pan with some coals inside a few inched off the bottom (prop up with rocks or something) and that will get it hot enough.