any time frame of 1HR and below is not safe. The divergence will be there and market might respond by 5-10 pips and then continue the trend. The previous suggestion of using trendlines is also very useful. If you notice back, all the divegence of 4hr on gbpusd have made quite some pips. It's also not safe to use divergence method on any base currency with a yen attached to it. Hope this suggestion helps.
Strings.