What if you just release two streams of particles next to each other in parallel? Then you don't even need the double slits. See if their waves interact, and you'll know whether pilot waves are real or not, will you not?
If the Copenhagen interpretation is true, and the waves are just abstract values of probability, then they won't interact, and you'll get two areas where the particles are distributed. Otherwise, if the waves interact due to pilot waves (Bohmian mechanics) being more accurate, then you'll get distribution with combined interference from both waves.
Has this been tested before? If not, could it work, and, if so, did it work? What would the results of this experiment mean, or would they mean anything?