Thanks for the suggestions! I'll give the Krakus brand a try. I've tried to explain what I'm looking for to the chap that owns the Polish stall in the market, and he's given me some to try but I must not be able to explain what they are well enough because they've not been right, one was almost fizzy

. Also, the ones from Lidl and Aldi are edible, but I wouldn't put them in a sandwich
Don't knock a peanut butter and pickle sandwich til you try it, it really is better than you'd think. I ate them for lunch (with Annie's Mac and Cheese) every day when I was last in the States. My husband was disgusted lol.
A co-worker is going to Florida and he'll get me whatever I request, but I'm afraid I can't wait until the end of June! I may ask my sister to send some of the relish.
Thanks again!