What does “grill sim” mean? See below for context!

In this song called “this could be love” by Alkaline Trio.
The chorus goes (yes, it’s dark, twisted lyrics)

The song: [youtube=https://www.youtube.com/watch?v=fy_eL0VYqRg]

[quote]“Step one: slit my throat
Step two: play in my blood
Step three: cover me in dirty sheets and go laughing out of the house
Step four: stop by at Edgewood Creek, and rinse your grill sim hands”[/quote]

My question is, in the chorus what does “grill sim” hands mean?