.
I don't know if it will work on Grease or not. My block had been cleaned years ago. But it had gotten rusty from just moisture in the garage of the guy I picked it up from.
I would pressuse wash off as much grease and crud as I could before dunking it.
The sludge I referred to in that first picture is rust and vinegar mixed together where it was coming off of the the iron. There was no grease on my block when I dunked it.
