Just don't to it if you have collector drones out and about, they pick it up and shove it straight back in again. Until they fix this, when using drones, firstly I spend more time in the refinery flushing the stuff I don't wont before it gets to cargo. I also always do the tidy and Jettison after my drones have expired and before I launch the next set, I jettison, boost far enough away so my drones wont go play fetch.
One time I had to close my cargo hatch and run away with two drones chasing me to put the cargo back in hehe. Comical at first but eventually annoying.