Depends on the country, I wouldn’t try it myself. And I’m pretty sure „well I wasn’t even allowed to inspect my luggage, i have it on paper“ isn’t a good defens

Depends on the country, I wouldn’t try it myself. And I’m pretty sure „well I wasn’t even allowed to inspect my luggage, i have it on paper“ isn’t a good defense, because then you shouldn’t have taken it in the first place. If you bring something onto a plane, it’s your responsibility. If you don’t know what it is, don’t take it.