I always found those kinds of settings annoying, what kind of country would try to get rid of someone they summoned just cause their skills sound shit? While keeping them alive and safe would be cheap, offing them can only backfire (friends might become disobedient) and is a waste of valuable resources (perhaps most of all as a hostage). Knowledge of another world is always worthwhile (even if it is same or lower tech-level, at least stories could be sold if the world isn't a serial-offendersummoner), and otherwise could be interrogated used to get information that helps you keep the others happy and compliant.
Worse is how in many of those stories, the thing classified as trash is only such relative to the others but is above-average when compared to peasants, making it worthwhile to give the person a commoner's job.
If absolutely nothing else, rather than throwing away, why not use as an exotic 'servant'.