Can I reach out to previous people I interviewed with for FT?

Had some summer interviews where I meshed well with some groups but was a bit unprepared at the time and accepted an SA elsewhere, was wondering if I can reach out to the same people who interviewed me for FT recruiting ? Is this looked down upon? What if the groups fairly small and I met most of the team already- would really have no other option here?

Also any advice on how to reach out / get the convo started would be greatly appreciated.

Thanks