oh, no! Grille musubi disaster! I've never used nonstick grill toppers, so I can't give you advice on it. I've always just used regular grill, throw the musubi on top, then let it go. Did you toast the musubi for a little bit first, then add the seasoning/sauces or did you douse then toast? It would probably help if you toast slightly first, then douse/brush, then continue toasting.