People who survived petrification were revived using Senku's formula, with the exception of Senku and Taiju. How were they able to revive without any formula?
It is hypothesized by Senku that both he and Taiju were revived because they remained largely awake throughout the petrification.
They both were revived due to the presence of nitric acid from the guano cave. This presumably took time and a significant amount of acid to release them. Reviving normal people takes the stronger etching compound Nital.
However, since we know both Senku and Taiju were shown to be actively thinking and concentrating on a particular goal while petrified, this may account for how they were revived more easily than, say, the birds.