I found that carbonation helped to cut the mucous a bit, but there was a time when I had too many burns & sores to tolerate it. Diet is probably easier on the teeth.

I used Epicuren lip balm and it was very effective. We tried a lot of different things (my wife is an aesthetician and specializes in that sort of thing).

ANYTHING can trigger nausea with Cisplatin - especially odors of any sort - perfume, food cooking, etc. There have been many threads on managing nausea if you search the archives. Stay in touch with the doctors on this. There are many different anti-emetic medications out there. I also found that the nausea episodes got worse the more chemo infusions I had. Everyone responds differently to treatment so his experience may not be as severe.