If you have never used Bar Keepers Friend, you are going to want to give it a try. I've never regretted it.
As with any product you have never used, be sure to read the instructions/cautions carefully. Also, know what products you can and can not use on your household items. Use the wrong thing and you could destroy something valuable to you.
I have a skillet that gets used all the time to brown meat and many other things. Sometimes it just doesn't get as clean as I would like it to after a normal washing.
Enter stage right, Bar Keepers Friend:
Just a little bit of scrubbing. Seriously, I think maybe it was under a minute. See the difference? I've seen pans a lot worse than mine and even with a little bit of soaking they can look like new again.
And this pan is probably the 2nd most used pan in the kitchen:
I {love} shiny, and this just makes me smile!