Bareel Polish

OP, others will disagree, but I use Hoppes for my first clean on a swab after 20 strokes with JB Non Embedding Bore Paste. ..ten strokes, then another ten with Hoppes on another swab...then repeat that process with Ballistol. Then repeat with clean swabs or patches.

Some will tell you that Hoppes contains harmful acids. I don't know if it does or doesnt, but I figger if it works in a powder burner, it shouldn't hurt my air rifles, especially after the Ballistol rinse.

I won't argue the point, but everyone has to do what feels right to them.
 
Couple of thoughts on cleaning.

If you're going to use a petroleum based cleaner (WD-40, Ballistol, Goo Gone, Kroil, ect.) you must remove the barrel seal O-ring and ensure the barrel seal O-ring groove is completely clean prior to reinstall. The reason is that petroleum based cleaners will destroy the rubber O-ring.

Personally I don't like using these cleaners at all. I’ve tried it a couple of time and found that my accuracy is terrible for the next 200-300 shots. When it comes to cleaning I just pull 1-2 dry patches through to remove any excess lead, as that's all that's really needed.

Remember these aren't power burners so when it comes to cleaning the barrel don't treat it like one.


 
Buna-N is the most common O-ring material used for airgun seals and it is very resilient to exposure to petroleum products. I use Kroil, Goo-gone, and WD-40 for general bore cleaning and have never had a breech seal become cracked or brittle.

Regarding Hoppes, it is particularly effective at removing lead. This thread has an interesting video comparing various bore cleaners:

https://www.gatewaytoairguns.org/GTA/index.php?topic=158938