Hi all, I am an Italian physio living in Australia and I'll tell you my experience ofBell's palsy in both countries.
In Italy we usually treat the palsy with PNF, starting as soon as the diagnosis is made, together with the medical treatment of corticosteroids. Usually we can appreciate the first facial movements after 10 days and we get full recovery in 4-6 weeks depending on the severity of the palsy. Sometimes 8 weeks. We find PNF to be very effective. Frequency of treatment is usually 5 days a week till we get some movement, then it can be dropped to 3 times a week requiring though partecipation of the patient with home exercises. The frequency and duration of contractions is personal judgment of the physio depending on the response of the patient. Of course first rule is to avoid synkinesis and also to avoid a pure "manual" approach but trying to make the patient aware with lots of feedback and "self-feeling".
In Australia, I had lately a friend of mine affected. He went everywhere (Perth-WA) looking for some treatment by neurologists and physios, always getting the same answer "there is no treatment other than corticosteroids, you have just to wait for the symptoms to go, it might take months even one year". When I saw him it was after 3months the diagnosis and he had recovered only 20%. At Uni they told me they don't teach treatment for any facial palsy. I tried PNF on him and he was back to normal after 3 weeks.
Regarding electrotherapy and US, I never liked their use for any purpose, I think there are more effective technique in general. Anyway, I'd never use those stuff on a face.
Emmi