How do you actually use one?

What strategy would you have when using them?

There are a few options in play...

I think the most popular is Ojama Lock via Spatial Collapse, since it provides a quick means to locking your opponent up and you can easily apply a burn or other finishing technique.

Typically Ojama likes to be splashed as a "jam" technique against swarm decks, though you could also use it nicely to feed a special summoning of Fiend Megacyber or Lava Golem.

The release of Ojama support cards and the recent normal monster support might provide for an interesting tactic, though I haven't looked into it. I always liked to use Snipe Hunter with Ojamagic to give a massive shot of "bullets" to use. Maybe a fusion of the two is feasible.

That's my 10 bits...

Prob. use spatial call. and other stalls until you get ojama delta hurricane? I am not sure, but I've heard that you can OTK with an Ojama deck. I don't know how but I might go make a deck myself around these thong masters >.>.

I'd rather use the Ojama Engine, basically find a productive way to discard Ojamagic, in my personal preference, Snipe Hunter is an awesome way to expand it. Or set it for a Emergency Provisions boost.