It depends on the object height.
The problem the original poster is having is he's just learning them, so the object is small.
If he used your technique, he'd be coming at the wall almost horizontal, which is why he asked the question about his front brake. Because he's hitting it horizontally, his brake just rolls forward because of his body position.
The rainbow thing Dan is talking about means your weight is automatically more over the front, the force is downward into the object not horizontally across it, and your brake has a much better chance.
Now on larger stuff, over say 40" you're right, it'd be harder to do that rainbow technique, and your technique works because of where your weight is.
I generally either tap to front or use the rainbow thing depending on how high / what the object is.