2nd Godfather / Administrator
2005 Granite Xterra Off-Road
Join Date: Jan 2006
Just spray on the simple green and let it sit. If it starts to dry up, spray more on to keep it wet. I find it best to do this when it's not sunny (evening) as it keeps the simple green from drying.
If that doesn't work, you have some killer mud. My next suggestion would be Marine Clean, but it's much nastier to work with (it will burn your skin).