Believe it or not, BarchLoon is one of the best attack strategies for TH5 and 6 that I have ever tried. With this army formation, you can easily win back 3 star from other TH5 and 6 (and even from TH7 If you do it wisely).
I know this air attack strategies might be a bit difficult for most TH5 and 6 players, but it is pretty easy to have a decent win with BarchLoon, just check out the video beblow before you try it.
---BarchLoon Army Composition
Assume that we have maxed army camps. We will bring these troops into the battle:
10x Barbarian
20x Archer
26x Balloon
2x Healling Spell
Clan Castle: Hog
(Hog Riders (at least level 4)are the important element of this attack strategy. But, of course, you can still use this strategy if you don’t have a hog riders, although it will be a little bit harder. And if your Clan mates have no Hog Riders, Giants or Wizards will be fine.)
Here are some videos that can help you figure out the Barchloon strategy.