Here is what I've found to be the absolute best way to defeat those horrible buzzy, scratchy guitar jacks. As I say in the video, I find that 90% of the time it's the sleeve portion of the jack that gets dirty and corroded and causes this.
Don't be fooled like I was for years that the key is in the "tip" part of the jack. I used to spend way too much time trying to bend the tip terminal or clean it to no avail. Through trial and error I found that creating a sandpaper tool by folding a small square of it double and then rolling into a tight tube is the perfect solution. Best to use fine paper from 600 to 1000 grit.
I'm not saying the tip part of the jack can't sometimes be the problem (along with grounding and other problems). I'm just saying in many years of working on guitars daily, I now know that most of the time a dirty jack sleeve is the culprit. Use this guitar jack fix in good health. I think you'll find it will serve you well. cheers