Oonoki was a student of Lord Mu (The 2nd Tsichukage), the 2 of them weren't related in any way. However, Oonoki was able to learn the Dust release (Aka particle style in Dubs) from him.
Does this mean that the tsichukage can also teach kekkai touta to individuals with at least 3 chakra natures? (Kekkai Touta is a more advanced version of Kekkai Genkais and is a combination of 3 chakra natures).
No, it's not possible, maybe it's too late for the answer but anyway; the only ones teachable are the 5 basic elements (if the individual is compatible with them) and some Kekkai Genkais that are transmittable like sharingan etc. So the point is if the individual does not have in his blood you can't teach him how to use it or activate it, for your question, if someone does not have that Kekkai Touta you cannot teach him those jutsus. it's exactly the same with Kakashi, even though he could use up to 4 chakra natures but he couldn't copy any technique that's based on Kekkai Genkai or Kekkai Touta simply because he doesn't have that Kekkai Genkai ou Kekkai Touta. So mastering the 5 elements doesn't give the ability to use Kekkai Genkai or Kekkai Touta.
Kekkei Tota is like a natural selection, not being possible the teaching, or descent by bloodline, unlike Kekkei Genkai.
Fonts: https://naruto.fandom.com/wiki/Kekkei_T%C5%8Dta https://duniaku.idntimes.com/anime-manga/naruto-boruto/dimas-ramadhan-2/ini-perbedaan-kekkei-genkai-kekkei-tota-dan-kekkei-mora-di-naruto
