Here is what I did for a glossy, and it worked! Of course, I had a 2nd glossy that it did not work on, but still...

I had a lizard tail in the freezer already used for scenting. I bought a frozen fuzzy from Petco. I thawed it and washed it well to remove as much scent as I could. I took the frozen lizard tail and rubbed the juicy end all over the fuzzy. The snake ate the fuzzy!

That snake continued to require scented thawed fuzzies, but I no longer had to wash the fuzzy after a few times. A friend of mine had a glossy that switched to unscented thawed fuzzies after some time.

Give it a shot if you can. No need to kill a lizard, just get the tail.

Anoles have worked for many kingsnakes.