I have to say, I have never even heard of filling rat holes before. Indeed.
to be on topic (from me of all people

)
Is it not the norm on ebay for the buyer to leave feedback first? I always have and always do when I am a buyer.
I sent a friendly reminder to this guy I sold something to a month ago, that if he is satisfied, please leave positive feedback, and then I will do the same.
He writes back all indignant, that he is insulted that I did not leave positive feedback for him first, and because of this, he will not be leaving me feedback. ????