I use a compound painters use to clean greasy walls before painting.
It's called TSP, main ingreatent in Rutland cleaner.
I got mine from Lowe's paint dept. Be carfull, there's TSP and EPA TSP, you want the former.
It turns the creosote into a crisp crunchy that flakes off and falls into the clean out.
Warning, I have had the creosote flake off in large sheets and clog the flue, killing the draft.
Checking the flue with a mirror, didn't see any daylight, I dropped a short length of chain on a rope and broke up the larger pieces and removed them out the cleanout.
IIRC, I had been burning green wood. This hasn't happened since, as I now try to have seasoned wood available.
That was when I was newb wood burner learning about burning wood. Low air , lots of smoke and green wood.
Now I also monitor the stack temp. Keeps me from overfireing and/or makeing creosote buildup.
YES, I burn pine and my flue is clean. Live and learn and a couple scoops a week keep my flue clean.
TSP is not a cure all, I still clean out about a five gal pail of crunchies each season. They fall into the cleanout and not stuck to the flue.
May have to try the alum can trick, my boys are beer drinkers and never return the empties, got a large pile.