Not quite for aquarium use, but I have a tricky problem that I'm hoping someone can aid in? I have a piece that has a 1 cm diameter, press-fit into a stainless steel fitting. Looking through it I can see it is a bit hazy. Want to polish it or something. Need to be able to look through it and see a perfectly clear image. Anyone have tips to "clean" it. PS. No harsh chemicals, nothing heavily abrasive, nothing that will leave a residue is allowed. (needs to be in a super clean environment) Any advice!! Please!