I heard the words slightly differently, Fliss

I think it's:

*Most efficacious in every case

*"Brother Tony..." rather than "Rubber Tony..."

*Aunty Millie ... so they rubbed on medicinal compound...

(This change is a crucial one for the joke in the verse)
*Jennifer Eccles ... Now he joins in all the games


*"Lily, the pink, she
Turned to drink, she
Filled up with paraffin inside
And despite her medicinal compound
Sadly pickled, Lily died."

A very silly song, though none the worse for that, and always a good sing-along.