You want to fuck with other wifi networks (that you're not connected to) with the help of your own router?
If you cycle your SSID through a list of already existing SSIDs in the proximity then you might catch some device mistaking you for a bridged AP. They won't be able to connect to your own network, but if your script stops at an SSID that some device tried to connect to, then that device will potentially keep trying to connect to your AP, so you're essentially blocking that device from accessing the Internet.
But some kind of flooding is probably the best bet for a wider attack, although I don't think that's possible via SSID switching because devices aren't scanning for APs constantly. Maybe flooding an AP itself with authentication requests could work on some routers, you could potentially fill the router's whole memory and slow down the whole network to a crawl.
Search openwrt and dd-wrt forums for what wifi admins struggle with, then deliberately create such conditions.