A few days ago, I was climbing out behind an airliner that had departed about a minute before us. I was the pilot monitoring for a relatively new copilot and, during departure, I told him, "If we get rocked, stay off the rudders." The airplane I fly these days has a fly-by-wire system, but I knew that the copilot had come from a conventional flight control aircraft. I wasn't sure what his training had been about rudder usage during a wake turbulence roll event, but my company teaches us to not use rudder inputs in case of a roll upset. The danger is that you can exceed rudder force limitations, especially if you start moving the rudders back and forth in an attempt to recover from a roll upset.
During our departure, we got about a 15-degree roll left, then right, and then we were out of it. The total wake event lasted less than 10 seconds and then we were on our way, another basically normal departure in congested airspace.
The Advanced Aircrew Academy Wake Turbulence training module was recently updated and contains information regarding rudder usage during a wake turbulence event. The updated module also contains the latest ATC separation guidance, some cool new graphics, and website links to the latest information.