yeah i think it is certainly ethical to off them if that's what you want to do. I would say don't give them to others as there is a good chance they will let them breed and then money can be gained by selling which can cloud peoples decisions on what is best to do in that situation. I am a purest when it comes to africans but i don't see hybrids themselves as the problem, it is us who decide to sell on dodgy fish. there is no reason why you cannot keep them, if they get to the stage where they aren't working with the setup then you need to make a choice. if it was me, i would off them over giving them to someone else but that is up to you.