Also, has anyone else tinkered with Toxic Spikes? Venusaur is less common now, and Tentacruel will lose a sizable niche with Greninja gone, so grounded Poison-types are less of an issue. They help to wear down some pretty annoying defensive Pokemon such as Mega Sableye (provided you can avoid having them bounced back) and Mew, which helps you break down some defensive cores more easily. Even if you can only afford to get up one layer, that passive damage is still like switching into neutral Stealth Rock damage every turn, so it can really add up. The trick is finding a viable user of the move, but you could probably get creative with something like Scolipede (the one I've been using, personally) or Dragalge.
I think toxic spikes definitely have their merits but the main issue as you know is that OU is just ridiculously packed with flying type, steel type, and levitate (not to mention magic guard and magic bounce pokes). LO or sash Scolipede seems like a great user of them because he actually has a tremendous speed tier on the no-greninja-ladder and his STABs have plenty of targets like preventing latis from defogging, maiming fairy spammers, and significantly hurting metagross with a LO earthquake.
I love toxic spikes they're one of my favorite tech moves to run, I think I'll try to use them on an experimental stall/bulky team. I will try to use a poison type that can either reliably counter gardevoir OR reliably counter diancie -- having at least one of those damn fairies covered from the start, on top of having secret tspikes in the waiting, will be a good place to start a stall team. There are really limiting choices to make however because the psyshock/earthpower coverage that those mons bring is pretty tough to deal with.