You are allowed to use Search & Escape if you have no benched Pokemon, but...you would automatically lose.
Here's how it plays out.
~Announce the attack. Look through your deck for a Trainer card.
~If you find one, reveal it and add it to your hand. If not, then that's fine.
~You then have to immediately return Chatot G to the deck; you're still in the middle of attacking.
~After your attack your turn is over. At this point you have no Pokemon in play; therefore you're the loser.
A note, if an attack lets you search for cards and puts them into your hand, they have to stay in your hand, because once you attack your turn is over. You can only play them on your next turn. An effect like Call Energy/Call for Family is different, since it tells you to put those basic Pokemon on to your Bench.