This is probably the most common but incorrect statement I see all too often, and it's simply not true.
The instinct is still very much there, just like how many dogs will walk a circle to "lay down the grass" that is not there before they lay down, whether they have ever even seen grass or not, and same rides true for the clowns.
We have been seeing large numbers of clowns that refused to accept a host, actually accept a host pretty much immediately when they are given the RIGHT host, meaning the same species they would be found in the wild.
Tank bred or wild caught, makes no difference, given the proper species of anemone they will accept it as host pretty much right away.
Most reef sites now have a sticky posted as to which anemones host which clowns naturally as they would be found in the wild for this very reason, or there is a book out by Fautin and Allen, "Anemone fishes and their host sea anemone's" which pretty much has the most up to date and accurate list.