A320 can be sideslipped in either roll normal or roll direct law. In normal law the technique is a bit unorthodox - when required slip is achieved, bank is maintained with stick in the neutral, rather than with constant stick displacement.
On any transport aeroplane, working as designed, you can kick and hold full rudder, fly till your fuel runs out and nothing much would happen. AA587 got to extreme sideslip that ripped off the vertical stabilizer through series of large and rapidly alternating pedal inputs. Pilot induced oscillation lead to dynamic directional instability. Using the rudder to recover to wings level can save you when all roll control is lost. Otherwise it can turn out to be lethal.