I just get pickled and check they don't have sugar in. Or I get mixed pickle in Asda, it's pickled gerkin, cauliflower and onions in vinegar- not strictly on the list, well the onions aren't, but it is as low-carb altogether as just the gerkins.
Dill's a herb that's included to flavour the pickling of a lot of gherkins. Krakus use a lot of dill I think and their's are the yummiest gherkins, deffo!
I've googled dill and it looks interesting, I do like to try new flavours! I've always just bought the cheapest gerkins with no sugar in, so I'll take a look for ones with dill. I also have pickled cabbage sometimes too, and my dad just told me gerkins are the same as pickled cucumbers so will try them I thought they were completely different things!