I would have to guess your referencing The StochRSI or RSI when saying TA has any edge. While over a short term you may find profitable trades. It is almost certain if you relied on any TA indicator or multiple indicators alone. Over time you would loose more then you gain.
Either that or your saying "buy the dip" :P
Actually that is the opposite of what I am saying. I am saying that certain price action patterns tend to repeat themselves, such as overbought and oversold conditions combined with several other indicators provide for scalping opportunities.
So more alike to "head and shoulders" or "3 buddhas"