If it can reach a junction box that has enough room and the conduit was more than 2x it's body width, then yes I would think so.

Doing a search results in MANY different opinions if a snake can move backwards or not. Didn't find any absolute credible answers, just lots of contradictions. I can't remember if I have ever seen a snake actually 'move' backwards before, so I can't say. Many people were calling the fact that a snake can 'pull back' the front half of it's body, as moving backwards. But that is not correct. That is just pulling it's front half back, then moving in a different direction - forward.