Yeah, the AFZAL (all I can get locally, doesn't stack up to the Romman I smoked alot of lately) shishas are almost sickly sweet, and give me this burn in my throat. They just aren't a pleasant smoke. Had some AFZAL Rose mixed with the last of my Romman Raspberry, and it was an intresting mix, but man, the headspin laid me out flat on the couch for like 5 minutes. Sort of good, sort of bad
Back to the topic: Shisha recovery, if it's REALLY burnt, then it's done. You just won't get a smooth smoke out of it. If it just went harsh, it's too hot, take the coals off asap or you'll end up with burnt shisha and nothing you can do about it.