This kind of question comes up often, and I have a harsh opinion on this.
Using effects to fill the gap of a (missing second) guitar is a really bad idea.
Use effects only if you think it can add something nice to your role as BASS player. Not as pseudo rhythm guitar.
When the guitar is playing lead, then it's your time to shine as rhythm section. (Or whatever style you can play to support your guitarist... heck, even steal some lead play with him.)
You either need a second guitarist, or don't and be a trio.
There is nothing in between.
And it depends which music you play and what direction your band wants to go.
Sorry, this is all just in my humble opinion and experience.
My first band was a trashmetal powertrio, and I used a lot of distortion. But, because that's how we wanted the role of the bass to be. I would have used distortion even with a second guitarist. (And get lost in the mix... yeah, we were not that great.)
That said, some advice on the effects you want to explore.
I was never a fan of chorus on bass. (Sorry, I'm really not grumpy.
I prefer tremelo as alternative to where another bassist might use chorus. Depending how you use tremolo it can create a mellow sound. (With a bit of delay).
Lot's of choruses out there. The one I did use for a while was the BOSS CE-5. I liked it better than the bass version.
Easy to find pedal.
Hundreds of choruses out there, sky is the limit when it comes to price and function.
My favourite octave pedals are MXR Bass Octave Deluxe (analog) and EHX POG (Digital).
And sure, you can use octave and chorus togheter.
It may sound like crap, or it may sound awesome. Go out there and try it.
All IMO, IME and YMMV.
Originally Posted by Joe Milo
Better yet, what application would an octave pedal best be used for?