Potty training

My son turned two in December and I have another one on the way. My friend gave me the book Oh Crap It’s Potty Training and it basically says to let them run naked all day and watch for cues that they need to go potty and then sit them on the potty. I tried it yesterday and it was a disaster. He peed in the floor multiple times and wouldn’t finish on the potty. It got to the point where he was just done and didn’t even want to sit on the potty. In the book the author says that waiting until they’re ready means it’s too late but my other mom friends seem to have success with this. First off- has anyone read this book and had success and/or failure? Second off- do I keep trying or just wait until he’s ready?