Guerilla Pot Hole Spraying?

You don't need to use fill that hole, they just pass on the report to the authority in charge of the road. Just call up the highways department of the council direct (or TfL if it's a red route in London); they have a legal obligation to sort it out once they've been made aware of it.

But I like the idea of the spraying.

No, all you need is this:

http://www.tfl.gov.uk/tfl/roadusers/reportastreetfault/newfault.aspx

It's a one-stop shop. TfL pass the details on to the local highway authorities. Works very well.

(Tsk, tsk, TB, short memory? ;) )