Would orajel help with pain from a decaying tooth?

Not likely. Orajel is a topical anesthetic, but many toothaches are pain originating deep inside the tooth. For this reason, orajel is ineffective in providing significant relief. If your pain is from your gums, however, it can provide short term relief. The problem is you need to be very careful that you don't swallow too much. It's very easy to get too much which can upset your stomach. See a dentist.
Temporary only. Your body is experiencing pain because it is telling you that you have a dental problem that needs fixing. Oragel and other pain killers will only help for a very limited time. Get to the dentist and address the underlying dental problem. Anything else is just trying to fool yourself.
Yes. Orajel contains benzocaine, a local anesthetic that can provide temporary relief of pain for some patients with a toothache.
ORAJEL. It may help temporarily, but you need to see a dentist and have it taken care of before it gets worse. Tooth infection can cause serious health risks including death.