High Temp Clean Question:

Well, I have done them before...the high temp burns. This time though, I had just finished some filets and decided to clean it up for tomorrows smoke. I took off the DFMT to let her rip, but left the screen closed off, so it held steady at about 700. I just went to check and it is at about 550 now, but it burned at 700 well over an hour. Now though, the inside of the fire box and ring are bone white clean.......but I also had left the regular grid in there and now it is ash white too. What should I do that that now? Is it ruined? Also, the top didn't get clean like it has in the past......I guess I didn't fill it up with enough lump and I probably should have just opened up the screen too to let it rip to 900 or so.

Thanks!