Don't do anything radical!
I am occasionally approached by acquaintenance who ask me to sharpen their knives. Sometimes they hand me knife in a sheath that has not been out since they finished gutting their deer the prior fall! The stench is remarkable at best! I toss the sheath in soap and water to soak while I go to work first washing off the blade, and cleaning it up, and then sharpen it for the friend. I also spend some time telling them how to use, and HOW NOT TO USE their knife, so they don't dull it.
I use a three step process to sharpening knives, BTW. I learned it first from The Razor Edge Sharpening Book, and later, from Roger Needham, who sells stones at Friendship every year, right near the main entrance. He puts out a wonderful 2 sided, legal size instruction sheet that really does cover all the information you need to know about edge angles, care, and sharpening. I put a " Supported edge on the blades, by first putting a shallow bevel to the edge, using a medium or " Washita " stone, and then raise the edge up to put a wider angle, but a finer edge using my long Black Arkansas Stone. The final step is to use a strop to remove the burrs, and aligned the edge of the blade so it cuts in a straight line, without waves.
Stay away from bones and that knife will stay sharp for years. My friends have remarked about that. Where they were lucky to gut and skin out One deer with the knife before I sharpened it, they now are gutting and skinning 5-6 deer with the same knife.
I use the spray nozzle on the faucet to work out the crud that remains inside the sheath after it soaks with soap and water. I may use a .22 cleaning rod, with a rag on it, to go down the now soft sheath and wipe out more of the dried blood and crud. I Like your idea of using Lysol. I never did that before, but its on my list to try. I am only concerned that some of the chemicals in that product may dry out the leather unnecessarily, causing deterioration problems to accelerate. For sure, if you have that leather sheath in water very long, dry it over night, and then hit it with some saddle soap, and/or neetsfoot oil to recondition the leather again. I had one sheath that was so stinky with blood and guts, that we seriously considered cutting the stitching to open it up. Instead, I left it soaking over night in the soap and water, used a fine brush to go inside ( One of those bottle neck brushes) to pull out the crud, but most of it all came out with the rinse, because the over night soak with soap and water had rehydrated the blood and tissues enough that they lost their stickiness. I was very generous with my neetsfoot oil on that sheath, however, after we dried it out.
