Simple.......
Unscrew the bottle from the airsystem,
Dont carry paint in the same bag, airlines don`t like that.
Keep a magazine at the top of the bag so you can show staff what the kit is for.
Be prepared to have your bag empted and searched, only happened to me once and I travelled abroad loads last year.
o and lastly try not to get to upset when security empty your bag and then put everything back in on top of your recently purchased shocker and scratch it......
these things happen, dam spanish airport security.
Hope it helps.