Being able to run video clips backwards is totally dependant on the codec&settings those videos are encoded in.
As video compression codecs try to save as much bandwidth as possible, not all information is in each frame. As most people play video forward, most codecs are highly optimized to only store the difference to the PREVIOUS frames in the current frame.
That does not work when playing backwards, and you’ll get hiccups while the player is trying to find all information.
So ideally you need an encoding where each frame has all information and is not depending on previous frames.
I heard best backwards playback/VJ scrubbbing results with MPEG2 (encode with I-frames only). Also Animation codec, and a bit less PhotoJPEG.
For a more TouchDesigner-centric way (and also extremely fast), look into the Cache TOP, which saves videoframes to your GPU memory.
If you send a LFO into the Cache Select TOP, you can scrub video as fast as you like.