I am assuming that oral ulcers are like canker sores in the mouth. I get these time to time when I have bitten inside my cheeks or inner lip. I also get these time to time on my gums. Both are painful to say the least especially when I have had some in the back of my throat. The mouthwash is a good tip. An even bigger tip is immediately toss out your toothbrush and get a new one. You can also get oral medication to alleviate the pain and aid in the healing. One other thing that has proven to be effective, as well for cold sores, it tannin. Tannin can be found in tea and by placing a moist tea packet against the sore repeatedly, this has been proven to aid in the healing of these.
"IF I COME ... I'M BRINGING THE PAIN WITH ME"