Second Anointings have been performed by invitation with a G.A. taking you and your spouse into the temple, washing your feet and doing a specific ordinance.
Calling & Election is a spiritual ordinance and the Second Anointing is a physical symbol of it. Many have received the Calling and Election, but have never received the Second Anointing.
The temple ordinances of endowment and Sealing are not required for C&E, neither is the Second Anointing. There are plenty of people in both the Book of Mormon and the Old and New Testaments who received their calling and election made sure while they only had the Aaronic priesthood and did not have the authority or ordinances of the higher Melchizedek Priesthood. They couldn’t perform the ordinances of the temple. Yet they received the blessings and promises.
No general authority or secret exclusive temple ordinance is required for C&E. Besides, IF such an ordinance was required for all the blessings listed in D&C 76:50-70, then only those who had this secret ordinance would be resurrected with the just in the first resurrection and only those would inherit the Celestial Kingdom. Also, the LDS church does not teach the ordinance, you cannot prepare for it because they do not tell us what criteria we need to meet, you can not interview for it or request it and it is not being performed for the dead. If it was required, then the whole church is lost save a very few leaders of the millions of members of the church who will never be offered the opportunity to receive these blessing. That means the leadership of the LDS church are responsible for holding back millions of righteous and worthy members from progressing and receiving blessings that they deserve.