There are two possible ways to fade barbwire. One is to fade any trend close. A trend close in a barbwire is likely to breakout on the other end. So you could sell the high or close a bull trend bar or you could buy the low or close of a bear bar. However, this is dangerous since there could be a breakout that takes your stop out.
A simpler strategy is to wait for a trend bar breakout thats more than two ticks beyond the barbwire and fade it. The longer the barbwire runs and the stronger the breakout, the higher the chances of success.
If the barb wire is made of tiny bars ( smaller than 4t ) there is a good chance that you will get a failed breakout multiple times, essentially forming an expanding triangle breakout. You need at least 6 to 8t to the other end of the barb wire to be able to fade the breakout.
A barbwire after an extended move at an extreme of the day (b21-b24) often causes a reversal and you can swing some portion of your trade.