Here is a simple video, showing how to cook using a "Brasero" to burn logs into coals for charcoal grilling.The side bit ("brasero") is for the logs, when they are burning, the bits that fall have the heat that you want for a slow grilling.
You can also use charcoal, with or without the brasero (depending on the size of the coals).
Regarding the grill mantenience, its best to clean it when hot (with newspaper).
Hope this help.
This is one of the Argentinean Style Grill with "Brasero" we have for sale:
Discover your Inner Latino!
Señor BBQ, Melbourne's gourmet BBQ caterers.