Loop cleaning

[Hglazm]

So I've got a pretty nasty loop right now. My tubing is pee-yellow, the tubing has gone from clear to opaque, the block has gone from shiny-copper to muddy-brown.

I'm ordering new tubing and anti-bacterial gunk. But I need to know how to effectively clean out my parts.
I'm not comfortable using vinegar as thats NOT an effective way to clean metals without causing damage.. I've been recommended using a diluted base, such as thinned draino, to clean out my radiator and CPU block.

But, I figure, with experience you guys will have some input.
The radiator and cpu block will not be connected to anything so I dont need something tube-friendly.

I have used the search function, and I have read the cleaning guide, but it doesnt satisfy my questions.

[Dark Bishop]

I know it sounds weird but I always use ketchup for the blocks, odd but it works well. For the Radiator Id just say some near boiling water shaken well and rinsed several times.

[Hglazm]

Ketchup would work because of its vinegar, which, again, is not a proper way to clean off a metal. Also I dont exactly know how I'm supposed to put near-boiling water into my radiator

[Conumdrum]

You lay the radiator in the sink and pour in into the hole?

ketchup has just enough acid to assist in taking tarnish off. it's also sticky so it sticks to what your cleaning to with a toothbrush.

You are going to open the pump and block and scrub them clean?