When my mouth was really sore during treatment, I didn't use my trays because I had huge ulcers on the side of my tongue. I just brushed my teeth with the fluoride gel. I figured it was better than nothing. Also, I drank the regular vanilla Carnation Instant Breakfasts. When I was using my PEG I used 2calHN and tried drinking the stuff when I stopped using my PEG, and oh geez, that was nasty. I also couldn't stomach the boost and ensure, so I used the regular instant breakfasts (vanilla) from the grocery store for a couple weeks. I stopped using those eventually and started making my own smoothies with protein powder and now I can't stomach the thought of drinking another smoothie and even ice cream reminds me of them sometimes and kind of makes me want to gag!