Making pickles using dill weed: ideas for containing the particles?
The tea filter idea works well and is exactly what I would propose.

You can buy ready-made paper or fabric tea filters that are smaller than coffee filters and more porous. If you want to use metal filters, make sure they are not reactive (like stainless steel) or they can influence the taste of the finished product.

Put your herbs in a filter bag, tie off the opening and put it into the container of your pickles. If you need a lot of herbs, you should use several tea filters, each filled with 2 teaspoons of herbs.