Hi Keith,
sorry to take so long to reply to your Q here, and the email...
no, an ovation through an octave pedal won't sound like a bass guitar... it will however make an interesting low noise that you might be able to use!

- I've never tried putting an acoustic guitar through an octave pedal (I don't play acoustic guitar, being the obvious reason for that), but there's no reason why it won't work. If it's behaving strangely, it might be worth trying it with some other instruments to see if the problem is with the guitar or the pedal.
good luck!
steve
www.steve-lawson.co.uk