Find Grout Brushes Online
There is a solution for buildup that is thick, sticky, and sludgelike. It is called a grout brush and has been used for ages to clean wires and automotive parts. Old-fashioned brushes originally used pig bristles, but modern brushes use a collection of thin wires to thoroughly scour other metal surfaces. It is small enough to really apply pressure to particular points and can also work with small objects.
A grout cleaning brush is all about removing tough junk on something very hard such as metal and ceramic. It is not appropriate for most surfaces because the metal teeth are often hard enough to scour away material. Buy a bigger brush for large surfaces, but the small brushes are the most versatile. Check out a supply store that has a variety of solutions using bristles made from brass or steel.