I have been using a product called orange blast.  probably same stuff as
simple green with better smell.  i like it and cleaners like it because it
is dilutable with water for various strengths.  works great on the stove
top in the house and other stuff in the van as well at various strengths.

carry two bottles in the van.  a small diluted one and the large one at
full strength.
jimt

> Replacement isn't necessary.
>
> Turn the lid on it's back with the foam up.
>
> Soak liberally with Zep Formula 50, Simple green or any HD
> cleaner/degreaser.
>
> Let it sit and soak.
>
> Take it to a high pressure car wash and wash the grease outa the foam.
> Be careful not to bare down on the foam.
> Give the pressure wand some distance from the insulation.
>
> It'll all wash out.
>
> Stand on it's side to allow the water to run out and foam to dry
>
> Worked well for me anyway with a used oil soaked engine lid cover.
>
> Smelled good too.
>