How can I clean the grime from this rubberized sealing gasket on my Zojirushi Thermos Flask? This is mostly for hot water sipping, a yogic/Asian practice.
The location of its basically where the lid gasket seals down on the flask lower body. It doesn't have much reason to gather anything.
I'm not sure how water usage can cause such a mark or can build up from something else. Is it just a mark or some build up?
Ps: I don't know exact material of gasket on hand but it's a zojirushi flask if that helps determine a solution - Resolved: It is Silicone Rubber
What is it?
How do I remove it?
I've tried scrubbing it with a tooth brush and dishwasher liquid soap to no effect. This has worked on other areas/plastic parts but did not work here.
I don't have access to an electric dish washer, but if it would help dipping this in hot water with soap or vinegar or something, I'd be open to that as long as it does not destroy the product.
PS: I prefer non-corrosive, organic, or common household solutions.