Sorry Jase (@38mm), but despite trawling around industrial estates at 6.30am, being questioned by security guards and generally getting funny looks in my search for the "grittiest, grimiest alleyway" I could find, this is the best I could do in answer to your Get Pushed challenge.
This "alleyway" is a footpath called Tinker Tank which is about 20 yards from my house. I tried to make it look as gritty and grimy as I could but a bit of flowery prettiness just happened to sneak into the corner of the shot.... woops!
You didn't mention anything about smartphone shots - assume that means you like them ;0)
I did find a bit of gritty griminess in the form of a burned-out car which was fun to photograph (with a real camera!)