I do Filipino arts. We (the guys I work with) tend to do a lot of knife-on-knife, as well as some empty hand vs. knife. Drills (6 and 10-count, punyo sumbrada, hubud, other stuff) and all-out sparring at times.
Disarms are taught as well, but so much of the extra stuff that you must throw into empty hand vs. knife to make it work is hard to reproduce in a training setting, such as breaks, eye gouges and guntings at full power.
For trainers, we tend to use wood, resin or hard rubber. Floppy rubber doesn't really work like a knife. Also, we have well-blunted cheapo folders. You can work on deployment from carry this way, and the flash of steel makes it all seem a bit more...urgent.
As the night progresses, attack and counter speed tends to increase. Some nights are crazier than others. I can never get enough craziness, as it happens.