Not sure if this kind of "shock" ad would actually end up in any high quality candidates.
At least it is a nice change from the usual cookie cutter job specs.
Has any Github code or practices put you off interviewing someone so far?
What kind of dev test do you do? Question and answer or give them a spec to implement?
There is also an sql like interface in addition to the Q and K languages.
This is probably easier to get started than diving into Q if that is too daunting.
Is your issue that you need cash to fund business expenses or a developer to add features to grow the product?
If the latter and you are confident in quickly adding revenue why not offer some equity/percentage of profit in lieu of salary? If the product is interesting you should be able to find someone willing to take on the risk.
The whoishiring thread would be a decent place to start.
Would it be an idea to implement OpenID? This would allow you to pull the user details and means users don't need yet another password to access your site.
Since Flickr is starting to require a Yahoo login for access it may be an idea to start there.