A complete vocal channel strip with compressor & limiter, de-esser, equalizer, enhancer, delay, reverb, modulation fx, separate chorus and noise suppressor is part of Boss VF-1 algorithms.
I mean if you already own an unused Boss VF-1 then you can lend it to your singer. It cannot replace a "real" vocal channel strip.
A ducker is the opposite of a gate. That means that the signal will get louder when the control signal is getting quieter. Whereas a gate will mute the signal when the control signal is getting quieter.
Therefore a ducking reverb creates reverb when the signal (your guitar) is getting quieter. It's better sounding because there's no reverb while playing rhythm.