Keeping the grill grate clean and sanitary every time
I have a few issues with your goals and current expectations.


  Keeping the grill grate clean


Is this really desirable? In my experience, you get a lot of flavour from the burning off of the last meal. It's a delicious ancestor effect. Maybe that doesn't bother you.

But washing a cast-iron grill (my assumption, might not be) is also a bit hard on the material. Cast iron is happiest when it's covered in grease. Deep cleaning it between every use might (citation needed) shorten its lifespan.


  Keeping the grill grate sanitary


If you're using it like a grill, it's getting really hot. You've nothing to worry about unless you have commercial food safety standards to uphold. Even those don't require a daily deep clean (I'm sure that varies around the world).