Whether or not they are allowed to work is up to HR and their manager. I enroll them in a scheduled class, We do not, for the most part, do one to ones unless we are going through things again with someone who has not passed the skills portion. (Fortunately, this is not often). I have done them occasionally with someone who became ill during the course and we sent them home but that, too, is a rarity.
I think the team building portion is extremely important and shouldn't be skipped. There have also been changes since someone who is expired now has taken a course and I think they need to renew just like everyone else.