Yep. Strangely enough, we just watched the episode about a week ago on streaming (CBS All Access).
Frasier and Lillith head off to Nantucket on Sandpiper Air, piloted by Joe and Brian Hackett. They're going there for Frasier to give a seminar for $299.95 or some similar amount on how to be assertive and confident..Helen is a former seminar attendee and starts giving Frasier stuff about not thinking the class was worth it - in front of the whole new group of seminar attendees. Pretty funny ep - Frasier has a conductor hat on and is blowing a train whistle with some marketing schtick about "getting on the (confidence? assertiveness?) train".
Brian, Helen and Joe get into an epic smackdown with each other and things go TOTALLY off the rails..to the point everyone leaves and Frasier has to refund everyone for the seminar..of course, Lillith was never on board with the whole "pop psychology" aspect of doing psychology via seminar so gets to totally rub Frasier's nose in a "I TOLD you so!" way..
Wings was right up there with Frasier as one of the best TV comedies of all time, IMHO..
I remember my sister loved Wings.
I never really got into Wings...I occasionally will watch an episode. It’s been airing on the AntennaTV network for awhile.