That may have been true in the past, not now. https://arcreef.com/product/coralline-algae/You will get all the coraline algae seeds required when you get coral with frag plugs.
Unless the coral is fresh cut, and the plug brand new.
The bottle coraline is all snake oil gimic.
It will not speed up anything.
Coraline is a sign showing your tank has equalibium and near the end of maturing out.
This is not something a bottle can do, unless that bottle is Time itself.