What products do people use to clean up rustic/dirty internals?

[JDM_Joe]

Here is a before and after of the front arch and disks. After dusting it off and removing a few birds’ nests, it came out better than I expected.

Someone recommended I use some 10-40 engine oil with a tea spoon of brake fluid. A little bit of elbow grease and it has removed most of the gunk.

I was wondering if there are any other techniques? Someone mentioned tomato ketchup.

[AngelaS]

Wow they came up well. I’m going to be doing a set of brakes soon but was just going to be lazy and send them in to be looked at