I certainly do train players in my games that psychics are legal. I try to do it in a complimentary way, especially when their opponent was one of the recognized "best players": "So, this is a legal [show the Laws], and very dangerous tactic. It probably wins 20% of the time, loses 30% of the time, and breaks even the rest. It is a sign of respect of your bridge play that this person no longer just assumes they can do better than that by playing you straight up - he wouldn't do it to a weaker player because he expects to get 65% off them anyway."
Having said that, the ACBL has three categories of psychics that are subject to regulation: excessively frequent, frivolous, and unsportsmanlike (it also explicitly bans psychic controls and explains about "developing partnership understandings"). For excessively frequent, they say that it is definitely fine to psych as much as you like, but the onus is on the psycher to show that, as Zelendakh suggested, "I psyche 5 times a year and it so happens that I g[o]t all of those in a single session". One of the categories of unsportsmanlike psychics is "psychs against inexperienced players." If anyone can show a tendency to do that (as opposed to a extraordinarily-for-the-area high psychic rate in general, hitting strong and weak players alike), there are grounds for action (which is why I suggested the recorder or equivalent above.) See
this page on the ACBL site for more details.
(as a side note, the dreaded "three times a session" wording is in there. But please note it's very careful to point out that that is a tripwire for investigation (with reverse onus, but I see nothing wrong with that), not a hard limit. Frankly, I think in the current climate, "three times a session" is *well beyond* where the tripwire should be - I can't remember a session where there were three psychic calls in the *field* in a session without someone having replaced their system with "EtOH Standard". Of course, there are many places where they think "one time a session" is excessive.)
As a mentor or teacher, I try to explain that psychics are a valid part of the game (and to take as a compliment the first time a strong player does it against them). Mostly because nobody else does, so it *looks* like the opponents have done something illegal when it happens. I will, if people show interest, explain some of the "baby psych" or "tactical bid" situations (or even the "we don't promise anything, we're just asking, but we won't tell you specifically it could be zero+" situations) because otherwise the first time it happens they'll absolutely get bit.
When I go to sea, don't fear for me, Fear For The Storm -- Birdie and the Swansong (tSCoSI)