The ban on short selling financial stocks is supposed to be lifted on Wednesday.  Whether or not it is removed remains to be seen.  At the time of this writing, an extension had not yet been announced.

Did the ban on selling short financials work?

We really do not know since drawing a definitive conclusion would require a control group of financial stocks that had not been shorted.

However, the ban did not stop the continued underperformance of financial stocks relative to the broad market.

From Monday September 22 through Tuesday October 7, the Financial Select Sector SPDR, ticker XLF, declined 25.2% while the S&P 500 Depository Receipts, aka SPDR, ticker SPY, fell 17.8%.  Thus, the XLF lagged the SPDR by 7.4%, underperforming the broad market.