On 17 June 1867, Pius IX invited him to Rome, on the occasion of the prelate's ascension to the pontifical throne. In 1870, Charbonnaux took part in the council of Vatican City and was a member of the Commission of Oriental Ritual. At the same time, with other apostolic chaplains he studied the Regulations of the Society of MEP. The aim was to create a final draft, which was actually something he had already begun in 1859, at conferences of Salem. He went back to Mysore in 1871, where he worked until his death.
