When you use the real bodies of the candles, you're basically getting the average range of that entire consolidation channel. The wicks are just overthrows. Also, a few pips above or below the box doesn't count as a breakout. It has to be significant.
The hardest part about trading boxes is knowing when to get in on a valid breakout. Most of the time, what you want to see is a breakout and then a retest of the box barrier where the breakout occurred. The idea is to get in on the trade on a retest of the box level that was broken BEFORE price moves to your final target.
In this EA 4 hour example, the origin box on the left shows a clear break AND a retest of the box before price moves up to the first target. It moved up again for nearly 2 full box levels before dropping.
But in the second example I have down near the lows, the breakdown occurred and it never gave a retest of the box before hitting the final target. It just ran straight to it without a glance back.
Using the box method works pretty well overall. I'd say it could be used as a stand alone method but you have to be really patient AND you have to be prepared to set stop losses clear on the other side of the origin box. In this case on EA, stop losses would have to be a bit over 200 pips (based on the first box setup on the far left of the chart) so you have to keep trade size entries adjusted accordingly.
I still use the box method myself but only in conjunction with other trading methods to help qualify entries.