The vimeo video is showing a real video footage but I suppose you are already aware of that.
This is a very difficult scenario for any uni-direction PT renderer, including Octane. As a pointer/starting point, there are a few elements required, such as (non exhaustive list):
• An appropriate mesh topology, thickness, etc. Modeling is key in such scenarios.
• Non-clamping/limiting render settings, exaggeratedly lowering "GI clamping" or the 2-3 depths parameters, for instance, would limit the renderer for properly tracing rays and letting them "bounce".
• Light "energy", since using strong enough light values make a difference in terms of "energy" and so, bounces, caustics, etc.
• PMC would likely be the appropriate kernel for complex light transportation scenarios, but does not support all features as the PT Kernel does.