I think your little grandson is not trying to make you feel like a poor housekeeper at all. I think he is emulating the adults in his life. He sees the adults cleaning, so he is cleaning too. Monkey see, monkey do. He is too young to realize that some behaviors, which are just fine at home, are not automatically engaged in when visiting someone else. But he'll learn all that in time. For now, I would encourage him and tell him what a wonderful helper he is. I'd even buy some stickers and put one on his shirt every time he "helps" . :-)