We used to use a "rabbit pen" to steady dogs to rabbit (particularly the b#####d Springers) in the
uk. Basically an enclosure with some cover containing rabbits, and then reprimanding them for following up on their flush (rather along Peters lines)
Peter Moxon the one time doyen of gundog training in the UK wrote a couple of good books on this
I might have an old copy laying around if you are interested.