A319 Flight Attendant reported while at the gate the flight attendants were told by the Captain a fire extinguisher in the aft right cargo bin was activated. Passengers and flight attendants were deplaned.

Narrative

All FAs were called by interphone; by Captain. We were asked if we smelled or saw smoke. We all replied; no. He then told us of the activation of a Fire Extinguisher in the Aft Right Cargo Bin. He told us to do an arrival all call and deplane the Passengers. FAs then did an arrival all call. #1 then made an announcement telling the Passengers they needed to deplane; now. As our flight was already delayed from the original departure time of XA:34; and it was now approximately XC:20; the passengers were moving slowly. #1 had to make the announcement several times in order to speed up the process. As passengers were deplaning; I then; began to get a 'very faint' smell of scorched or burning cloth; in the back galley near 2R door. I asked #2 if she smelled it as well. After coming closer to the right side of the galley aircraft; she too; confirmed; faintly smelling burning cloth or something of that nature. I then tried calling the front end crew. But realizing they would be speaking with other personnel and not getting a response; I called #1 and told her that both #2 and I; #4 smelled a faint odor of burning cloth or something similar; which she relayed to the Captain. After all passengers deplaned; all FAs made a complete cabin check and also deplaned.