I've seen this moveset used before, and it isn't bad. I'm assuming you have prankster on this set.
Basically, with Swagger/Foul Play, you make them choose between trying to get off a powered-up attack or hurting themselves a lot and losing a turn, allowing you to get up more spikes and status conditions. This is even more crippling for Special attackers, who don't even get a boost they can use.
I'd say go for it. That set is pretty good in a lot of situations.
I think if you add Swagger you should get rid of Toxic. You'll be dealing a good amount of damage with Foul Play and Spikes anyway, so you won't need that. Thunder Wave is your best choice for a status move, as a paralyzed confused Pokemon only has a 37.5% chance of successfully using an attack.
Good luck!
