A.R.
Hi B.,
I know exactly what you're going through...I have 2 daughter 4 and 1 who are hardcore thumbsuckers! I also love that they can self soothe when they need it!
My older daughter got sores...and I have the best treatment! Put lanolin on the sores. The same lanolin that you can use on your nipples when you are nursing. I would put a thick coat a couple times a day...and it would heal pretty fast. It creates a barrier...helps heal and it's totally non toxic and doesn't really have a taste. I used lanolin on myself when I was nursing...and have found that it is also great on chapped lips!
Good luck!