Folder Training Options: There are many options for training blades. One of our favorites is the Kershaw Emerson E-Train. The trainer has the wave feature, which allows for rapid one handed opening. The blade is also high quality and smooth allowing for safe training that is also durable.
If you took the EDC Karambit course offered by Tiga Tactics, you might want to consider a Karambit option. Fox knives makes some of the nicest folding Karambits around and it comes with our favorite one handed opening wave feature.
When other self-defense options are not allowed or available, sometimes something as simple as a high quality pen will have to fill in. We don't recommend ones that are "tactical looking" or have hidden blades in them, typically if those are allowed you would be better off just carrying a knife. Both have many of the features we like including looking relatively simple, hard metal body, wider base to support your thumb/avoid hurting your hand when striking a hard target and has a pen that isn't opened by clicking the back.