Grandparenting Discipline

When I became "MiMi" I made a promise to myself to never do to my grandchildren what I watched my Mother doing to hers. "Don't sit there, don't touch that, come back in here, don't go in that room, stay inside, stay out of the kitchen, I'll get it.." Etc., etc. My Mother was not your typical "warm fuzzy" Grandma and as a result neither my children, nor my nieces and nephews ever enjoyed their visit to Grandma's and went only to see their Papa. My Mother had/has favorites - one of her grandson's and his children, period. She's really not interested in anyone else. My nephew is aware that he is singled out/favored and he doesn't like it. He doesn't want to put a wedge between himself, his brothers and his cousins, and there isn't one. His brothers and cousins are okay with it. They know how Grandma is and they're fine with it. Since their Papa (my Dad) passed away she hasn't had many visitors and now complains that she has been put on the back burner. Interestingly enough where she has put everyone else..

In any event, I vowed not to be that kind of Grandma and I'm not but my grandson is now to the age where is knows basic right from wrong and I'm trying to teach him what is acceptable in "MiMi's" home versus what is not. I am teaching with love but am having difficulty with disciplining him when he does not behave appropriately, i.e., throwing food to the dog, getting into "MiMi's" jewelry, etc. My son has a time out chair for my grandson but I am reluctant to use it.

Just wondering if anyone else faces this issue. I welcome and am open to all suggestions, so fire away!