On Thu, 06 Sep 2012 18:34:03 -0400, Frank
wrote:

Use a degreaser.

http://www.supercleanbrands.com/products

(I have seen oven cleaner used before)


I'd tend to try mineral spirits or some light hydrocarbon on the filter
and the stuff you suggest inside the house.

My bride has soaked a filter in hot water with TSP (the red box). TSP
cuts grease easily.

The degreaser above has no phosphates.