Marcus Lemonis was going to get up close and personal with his audience at the iCONIC:DC conference on Wednesday, whether they liked it or not.

The event, held at the Warner Theater in Washington, D.C. was co-hosted by Inc. and CNBC.

After taking the stage Lemonis, star of the reality series The Profit, told the story of his difficult childhood, which he said he had not related on television. He grew up in Miami, after being adopted from an orphanage in Lebanon, and was molested by a family member as a child. By eighth grade he was overweight and had an eating disorder, and ended up in the hospital after he inadvertently dehydrated himself. He didn't have any friends, and attended college as far away as possible--Milwaukee--to give himself a fresh start. He didn't feel that he fit in there, either, and went so far as to contemplate suicide.

"I told you that story to create a connection with each of you in the room," Lemonis said. "I would be pretty certain that you would be comfortable telling me just about anything now... I'm not the smartest guy, I don't have the most money. But I do have the ability to take off the window dressing and be totally raw and totally honest and get you to be the same way."

Then, he said, "I want you to tell me something that nobody knows. If I have to tell you things and be vulnerable, then you do, too. ... If you look away from me I'm probably going to pick you."

Both of the people Lemonis picked from the audience went along with the idea. One told the story of how he had considered dropping out of college, and had deceived his family about his progress toward graduation. Another talked about being trapped in a room at a neighbor's house, being suffocated by the smell of fast food, and being unable even see a McDonald's commercial without having a flashback.

"If you're making a decision to do business with her, or with someone that's not vulnerable, who are you going to pick?" Lemonis asked the audience.

After making his point about vulnerability, Lemonis talked about the three pillars of his work life: people, process, and product. "The element of people in my three P's is so deep and so real that I sometimes feel like I'm a therapist," he said. "What I'm really trying to do is understand the psyche of the person I do business with."

Lemonis also extolled the virtues of doing deals on handshakes. It allows him to see how trustworthy the other party is, he said, and often speeds up progress. "If we sign a piece of paper and you're a bad person, you're going to be a bad person whether we sign a paper or not," he said.

And, he added, it sometimes gives him an out: If he's agreed to put $800,000 into a company, and he doesn't like the way things are going, a handshake deal allows him to bail out after the first $400,000, say, without legal consequences.

"I'm going to encourage you guys to do the smallest of business deals on handshakes," he said. "There are going to be times when you get screwed. But that's on them, not on you."

Lemonis then asked if anyone in the audience had an employee or direct report that they wish didn't work for them. When about half the people stood up, Lemonis announced that the other half were liars.

Then he started a dialog with one audience member, a government contractor who had had to take on employees assigned to a particular project when she won the contract. Lemonis said it was her fault that the employee wasn't performing as she would have liked. The entrepreneur hadn't made made her expectations clear; or her company culture wasn't strong enough; or her onboarding process was flawed. "I know you're not happy with me right now," Lemonis told the entrepreneur. "And I'm OK with that."