Personally, I haven't done any of this. I am studying.
Doing something like this might be difficult if attempting to do it with a cop. One might have to go through the courts using Karl's process, which is really the process that was being used in the early 1800s. It's easier, now, except that most people have forgotten it. And attorneys don't like it because it cuts attorneys right out of the picture.
In one of his talks, Karl spoke with a guy who was actually doing this. I haven't heard the results. If or when the first person wins, it might be precedent for, not legalizing weed, but rather, making it not illegal.
Karl has won big in traffic courts, for himself, using processes like this. Karl's biggest successes in getting property back revolve around parents getting their kids back from CPS.
Listen to the videos.