i am sure you remember jim'll fixit? i remember on one episode, where a boy dreams of being a doctor, so jim fixes it that he spends a days with a doctor in hospital and gets to do trivial examinations on patients. a female patient is lying barefoot on a bed and the doctor suggests that the boy...
i too remember this, i was very young but it was certainly a key moment in discovering that i had a foot/tickling fetish. that along with seeing sarah greene barefoot on saturday superstore were indeed seminal moments.
The Avengers
there is also another choice episode, not sure which one were steed briefly tickles emma peel's barefoot with a feather, she lets out a gasp and pulls her foot back.