Don't Let Sodium Bicarbonate Scare You. It's Your Friend.

I am so glad I found this out. We are working hard in the Peña family to eat better and better and we must say that our weakness is the frying pan, but along with the obvious also come the oven wall oil/grease drips and the grease grill-filter covering our fan over our oven turns brown and so the guilt makes us fork up between $11-$23 for a new one several times a year. Not anymore...
You only need:
water holder (bucket, pot, etc)
water
old toothbrush
sodium bicarbonate A.K.A. baking soda, water softener

Get yourself a small bucket, plastic pan or even a pot fill it with the hottest water your faucet will give you (careful don't burn yourselves, doesn't have to be boiling)

Add a little baking soda ( I used 1 tablespoon for 1 gallon)

Sit your greasy oven grill-filter half way into the solution and lightly brush off the grease. Extremely easy. The tough part is disposing of the greasy water later.

Pour the dirty water into an old cleaned out juice or milk container, cap it and label it. Put it with your recyclables or drop it off yourself to the nearest Bio-diesel station or other recycling station and they will separate it and most likely reuse it.