You will have a hard time finding lye or sani flush to degrease traps.
Some wash in a degreaser on new traps, I wash them in sopy water and wipe dry,to remove any oils and grease.
I use speed dip--but I mix with coleman fuel--not gasoline. I also thin it down more than the 4 to 1 it says. I also continue to stir the mixture as I dip.
Tom