Train about 2-3 dragons and half of the remaining space for balloons and minions. The exact amount is flexible, and the troop level isn't necessarily so high. I would recommend at least lv2 drags, lv4 loons and lv2 minions.
You would like to find a base that has most/all air defs clustered together. It would be optimal if the wizard towers are close to each other too.
Lure the cc troops and kill them with whatever needed. This could be crucial especially if there are dragons in the cc which would vaporize your balloons.
Start the raid from the side where most air defenses/ wizard towers are. Place troops in the following order:
First place all dragons.
Then put down a thick line of balloons.
Immediately follow the balloons by minions.
Use rage spell and healing spells carefully.They are used only when the balloons needs them. Try to cover as many (air) defenses and balloons as possible. You want to make sure the balloons (or maybe the rest of your army) can stay in and use the spell wisely during the whole duration of the spell.
Send the heroes behind the air troops to clean up. You may also use them as tanks/distractions or use them to kill the enemy heroes.
Sit back and enjoy the mayhem!
Mechanism-- The balloons are mainly the tanks. They soaks up air defense hits for the damage dealers, i.e. dragons and minions, behind. The spells are meant to speed the balloons up and help them last longer. While the balloons destroys most defenses and were wiped out, the dragons and minions survives and take down the rest of the base.
this is a costly but mostly 2-3 star strategy for th8-9s vs th8. Its a guaranteed victory for most time, and its surely a reliable alternative for balloonion.