Gospel.I always get a porter, one of the guys in white shirts, to go through customs, and I almost never get stopped. They are all friends with the customs guys, who know that stopping them means delaying them from earning the next tip. As you go into the baggage hall they ask if you need help and you say yes. You just tip them when you get out, I usually give US$ 10 for a couple of bags.
The last trip, everyone was in one line and the porter walked past them, went to a closed desk where a woman was doing paperwork, she just glanced up, smiled and me and waved us through. The time before, we were in the line, the customs guy saw us, he pulled the two people in front of us over for a check and then waved us on. Both times, the porter had been chatting to me and had said that we wouldn't be stopped.
I would suggest you put the phone in your handbag (purse), they have never asked me to empty my handbag or put it through the scanner. Or in your pocket if you have one, again they have never asked me to empty my pockets.