I'm a 34 year old guy, I should know how to do this sort of thing by now but I don't get it.
You go round Aussie households and their BBQ gets used daily yet you can see your face in it. We keep ours under a protective cover in a shed and yet it looks like a warzone when it comes out. Spent about an hour getting it vaguely non-filthy and then within 5 minutes it's black again.
So where do you stand on BBQ cleanliness? If it's charcoal, just accept it'll always be a bit grubby? Clean the grill whilst it's still hot or leave it to soak for 3 days after? Blast it with a hose? Buy a new one each year?