Singles Subway is a perfect playground for Acrobat Archaeos. I used it quite a long time, because I had one on my ingame run and even without specialized EVs, it OHKOed a lot. It´s better as a lead, tough, because it really can´t switch in.
Other than that, Doryuuzu obviously destroys in and out of Sandstream(better with it tough). Shell Breakers work well(those who are resistant/neutral to Aqua Jet in particular), because they can OHKO lots of mons. Cloyster with Icicle Spear is on top, obviously. For playing it save, White Herb is actually a nice option there.
Basically every strategy that worked in Battle Tower until now, also works in the Subway. Just watch out for Dreamworld sets(Contrarian)