Debarghya, I'll try and get through this post with no typos. I looked at my last post in your thread, and I'm thinking, "I need to take an English class."--lol.
The stochastics oscillator is the one I use as the most nominal part of my methodology, but as a confluence with other indications, it is very useful.
Personally, of all the oscillators, it is my favorite because it gives the truest OB/OS signs, the truest divergences, and I think it is the best momentum indicator of them all.
One of the reasons you need a confluence in order to signal an entry is that PRST made an interesting point. The answer is "no", you do not enter long if it is OB, but you could still get another strong spike in the same direction.
This is where using other TF's come in handy and are needful. I could conglamorate all the USD pairs from Friday's action, but I won't. I'll use just the EUR/USD as an example. It was forecasted all the respective pullbacks on Friday. In just evaluating the stochastics, it was highly OB on the hourly, 4-hour, and daily, but still pointing straight north on the weekly. Therefore, it is safe to say the market is going to make a correction of the larger trend only. There is no trend reversal, but a pullback within the larger scope of things.
Confluentially, there were many strong indications with all elements of the ichimoku, standard deviation channel on all TF's, and my proprietary S&R's to signal this temporary reversal.
In summary, I like to use the stochastics as a warning light. If it is OB on the hourly, then check the 4-hour to see what is says, then keep working upwards to see what kind of agreement you get. Check the confluences with other indicators to see what they say. Once the package deal comes together, then confidently enter your position and enjoy the price action in your favor.