I worked for a company many years ago in the UK that did one day courses for folk wanting to join the airline industry as cabin crew.
I personally think the course is a waste of time and money. The only people that are going to benefit are those that are clueless about the aviation industry and want an insight into the role of cabin crew.
I think everything we taught in the one day course candidates could learn from someone already employed in the industry i.e. a friend or relative employed as cabin crew.