You usually have to clean up the grills, but a good fire does that, after you can quickly brush off the elements remaining. Not too bad

Using aluminum is a great idea, however it's a bit problematic and sometimes is hard to cook with, it catches fire if not a heavier brand, and depending on how experienced the grille is they also have disposable grills to put over the parks metal grill. That's probably worth looking into.

Use aluminum foil