That sounds like a good way to catch the oil while being on the cheaper side of those metal/rubber troughs.

I think I ran into the metal they make those out. It was a jewelry box made out of a very bendable material that acted like and looked like lead.

I want to say it was antimony but I did not research it. I believe it was the material of choice to make the older toothpaste tubes out of.
No idea where you can buy a sheet of that but it must have been cheap then!

Plastic costs and the FDA probably put the end to that. Maybe that's why it's coated on the outside with nitrile now!

Gun hobbyists/snipers added it to their casting lead used in making their bullets. I think it helped put a touch of toughness in it so it left less residue in the barrel and slipped better down the rifling grooves.

I will try you bottle trick sometime.

Thanks,
Phil