Good afternoon. Has anyone dealt with stomatitis? My child is almost 6…

Good afternoon. Has anyone dealt with stomatitis? My child is almost 6 months old, is moderately fussy, and I just happened to notice two deep sores on the upper palate. Holisal seems to be for children older than 3 years. For now, I'm soaking the pacifier in chamomile and furacilin (we don't even suck on it, just chew it) and trying to cope with whatever I can. How long does this last? It’s impossible to reach there with a cotton swab; he doesn’t even want to open his mouth.