washing dishes-is grease and food safe down sink drain?

yankeeslover wrote:
so flushing small food particles/ dirty soapy water down the toilet into the black tank is ok? wont plug it up at all?

No. When you think about other things that go in there, you're just, well, cutting out the middleman, so to speak. And the most important thing to do with a black tank is make sure there is plenty of water in it.