Old Potatoes and Dead Bunnies, or What is That Smell?

I have a pretty serious kitchen stink I'm trying to deal with today. The Vansome has taken a lengthy break from his cabinet building project, so I'm operating on half a kitchen. The corner between the stove and sink has just been a black hole, except that all the crap in it is painfully visible. It was just the remainders of the old cabinet without a countertop, kinda like open shelving, only not useful or attractive. So it has accumulated large amounts of stuff I don't use often, and boxes of trash bags, and loose Kroger sacks.
I have been smelling a faint shrimpy smell around the sink for a couple of days, but we had shrimp last week so I just cleaned and cleaned the sink and the trash can. I cleaned both drains with baking soda and vinegar. Still a stench, but by yesterday, it had reached the level of kitty poop, so I was looking for a Beans accident now that he doesn't have an indoor litter box. Poor Beans, being falsely accused, and he really is a good boy about that sort of thing. I knew it wasn't Joe because he only pees on stuff when he's mad, and he has never pooped on our stuff. Nairobi was famous for leaving tokens of her dissatisfaction with us, but the boys don't do that.
Anyway, back to the stench in my kitchen. After doing a thorough search, the Vansome and I discovered a bag of potatoes that had somehow gotten lost in the black hole. It was so old it had liquefied, and the stench was unimaginable once it was exposed to the air. We threw out everything that it had leaked on, ripped out the rest of that cabinet, and scrubbed everything down with large amounts of Odo-Ban and Lysol. It's not helping. The smell is even stronger today and it's more than a little upsetting. I've got baking soda and vinegar on it now, and that helped for a while, but I can smell it again now. It has soaked into the concrete and I don't know how to fix that.

Shortly after the Vansome and I got married, during the first snow that winter, March Kitty left us a dead bunny at the front door, sort of a Welcome to the Family present for the Vansome. He was a little off mentally, that March Kitty, but you can't say he wasn't thoughtful. Out of gratitude for the gesture, the Vansome thought it would be nice to move the dead bunny to the garage so that March Kitty could snack on it in warmth and comfort, out of the snow. Wow, that was not smart. Probably the worst idea the man has ever had. The smell when we opened the door the next morning was unbelievable. For years later we would occasionally catch a whiff of dead bunny in the garage. Years. I can't have a stinky kitchen for years. My house is too small for that.