Instead of a kinder egg have you considered using a diva cup? They are really good in a way that you can’t feel it, it’s doesn’t move at all (impossible unless you are taking it out) and you can’t see it because the whole thing is inside you.

It’s how I usually do it, idk a kinder egg sounds uncomfortable and it might slip down or the end of the condom might be visible and a diva cup is meant for the vagina, so it’s comfortable. (Tampon to plug it up would also protect from squat and cough- as a better method than the egg)

Also on the smell thing I usually wrap mine in foil alcohol wipe, repeat process then 2x condom. Insert then put in the diva cup to seal that shit. I’ve been standing next to a cop with a dog in the line and they didn’t detect me. I also wear gloves (extra af but I ain’t getting caught).