You should really deal with echo before you record. For example:
- Choose a room that does not have too much echo.
- Use directional microphones close to each speaker, or tie-clip microphones.
- Place sound absorbent baffles in the room to absorb and break up echoes
Trying to remove echo / reverb after recording is very difficult and often fails.
The technique described here sometimes helps a bit: Noisegate Plug In doesn't appear - #14 by steve