The old adage applies here, "data doesn't lie". As a professional quality engineer let me just point you to some real testing that speaks for itself.
I found this on this forum when I searched ("method to prep for paint"). What came up was a post titled "Dan Gelbart Fabrication Tips"
When in doubt always test and verify any opinions. This video shows you how. It is spot on correct. (Side note, I will condone the use of Acetone...it does work as a fair degreaser, BUT ONLY prior to using the product in Dan Gelbart's video.) And an unequivocal NO on alcohol. Take a look. Again, is 100% absolutely correct. Try this link,
https://www.youtube.com/watch?v=x7onZGqrYyY
If that doesn't work, just search forums here for Dan Gelbart.
Key is always validate any opinions you get on here. Point for this post is do the so called "water test" for your own evidence.