[scarmig]

What's important is that it be an unconditional donation, not that it not be recurring. Yes, a one-time gift is (usually) not contingent, but you can also have recurring unconditional income that's not means tested.

Take out the means testing, and you remove the incentive not to work. They can still work, and, if anything, it lets people get out of the psychological hole where they have to make decisions that aren't utility-optimizing in the long term just in order to survive.