Stinky pickles - what the hell is that spice?

One of my favourite restaurants changed their pickles in the last few months. I like pickles - kosher, garlic, bread/butter, spicy, etc. But these pickles are...awful. Shape/colourwise, they are sliced lengthwise, translucent, light green, not crispy. But there's a spice in there that is just...nasty. Like sweat and bile mixed together. They are horribly pungent. The smell lingers in your nose. I picked it off my burger a couple of times, and the smell/taste lingers on the burger, and also on my fingers (even after multiple washings). I had thought maybe it was a bad batch, but they are still serving them, and I honestly think they are supposed to be that way. I now tell them "NO pickle", but I am just dying to know what the heck kind of pickles these are, and what that spice/flavour is. Does anyone have an idea? Thanks!