Best way of tackling this rust?

[Mike534x]

Hey everyone! This spot on the driver side rear panel where it meets the bumper is starting to bubble. I remembered from my last thread of the Chrisfix video for DIY rust repair, do you guys think it would work for this? Or is there a better way of handling it? The outside doesn't look all that bad, but after I got a better up close shot it looks like its goes a bit deep along the bottom portion of the paneling.

As far as prevention goes, the other panels appear to be fine and don't show much if any build up. Is there a way to spray fluid film behind the other panels to help keep it to a minimum? I did inside of the doors and tailgate. The tailgate some light bubbling on the inside lip portion, which I plan on sanding down and hitting it with POR15 and the same goes for my rear doors that have the same signs. Here's some pics of the rear panel, it doesn't seem nearly as bad as my avalanche was when I tried to stop it.

 

[Watchesandputters]

It's beyond prevention at this stage, it's more mitigation at this point. Toss your product of choice on the rear, don't flirt with correcting the rust between the bumper cover and fender beyond the aforementioned coating of choice as you'll be opening a huge can of worms with no satisfactory outcome.