My solution is:
Create custom table -> #__cck_map
This maps any relationships between contents.
I use logic to compare rendered (inital) value and stored values (final).
If initial values are not in final values then I delete from Map.
If final values are not in initial values then I add to Map.
Then in List and Search Types, I use a join form search content type on to Map.
And then from Map on to the content type I want the Map to be referencing
Pain in the butt, but is the good way.
After some googling, it is clear that you should not really put csv in to db field.
Should have own entry in table, hence map