Hey - actually you can use it topically - externally for sores, from radiation burn ( any kind actually) mouth sores ? Take a spoonful, put it in His mouth, let I melt - swish and swallow! If he already has mouth sores it'll burn! But I would suck it up and a few minutes later I actually felt better - then I began to heal. I still burned but not as badly! If full strength hurts too much, mix it with a little warm water and do the same - swish for about a minute - 3 depending on tolerance. It takes a few days to kick in, if there is already a problem with mouth, and sore throat! But for me it really worked. So I figure 3-4 minutes a day., was worth the pain! I used it 3-4 times daily. if there's a really bad sore - another poster on the forum would take tinfoil, place a drop on the foil and freeze, then he'd take the frozen drop and place it directly on the sore. That worked for him. Good luck! And re your previous post - your dad needs to take in his nutrition - liquid or solid it doesn't matter - you have to swallow both, as long as he is getting enough calories, protein, and fluids that's all the matters! take care