I clean mine by ordering new ones. After awhile, the plastic can become brittle and the neck can break off. It's a mess and a new bottle will usually prevent that from happening. As for cleaning, I have not found anything that will restore the transparency of the used bottles. I have tried tumbling polishing media in the bottle after cleaning the lead/powder residue. It's well worth the cost of a new bottle, given the effort and results of the cleaning attempts. I also use the bottle supports made by MEC to alleviate the bottle breaking issue. I use one size bottle on my progressives and that is large.