I have a question about using a public grill. I live in a complex with many other homes we all share a pool which has a grill that all the homes use. I know my neighbors use the grill to cook non halal meat and pork. Is it permissible for me to use such a grill to cook halal meat? Is the grill considered najis?

The grill is najes. If you are able to pour water on the grill to quickly purify it, then yes you can use the grill. Otherwise it is najes, and the meat you will put on it will become najes.