I have not seen that scene in years (for pretty obvious reasons as it is very much 'of its age') however I am sure it was Frank in the tar barrel that gave me my major tar and feathers kink!
Thanks for posting, I remember this as part of the Easter Special and I've been looking for it ever since. I wrote to the BBC as a teen asking what the 'tar' mixture was but never got a reply... This was up there with Great Race as a trigger for my fetish. Would love to recreate it.