How do you flush out liquid coolant?

I use distilled water at $1 a gallon from Walgrees and a $8 Ians silver kill coil for my liquid. The coil lasts for years and years. Here is what I do:
Every 6 months or so I drain it the best I can, refill it, let it run a day or so, then drain once more and refill. 6 months later I do this

Cleaning a loop, not a new loop: I do this once a year.

Wash hands very well, getting rid of hand oils.
For pumps and blocks, fittings, clamps, acrylic res/block parts.... not hose, tear it to smallest pieces, put in a bowl, heat water up not to boiling add 10% vinegar, when hot, pour over parts. Rinse in 10 min or so. Put aside.
The bocks will probably have some black oxidation. Take the copper parts out of the pile of parts you took out of the water. Dry well and pour ketchup on them, and set aside. Only the copper parts need this.
Rad cleaning: fill with very almost boiling hot water. Let sit 10 minutes, drain half out and shake for 5 min. Repeat till liquid is clean.
All the pump, block, fittings, and clamps, inspect, get in the tiniest corners with a tooth brush. Kind of meditative, time consuming, you learn a lot about o-ring size, how it all feels. Run a rag using a coat hanger and dish soap through the tubing, rinse well.
Rinse all the parts and hose with distilled, dry then really dry with an air compressor if you have one, not a requirement (nice extra step to get rid of water spots). Don’t need to dry the inside of the hose.
Now on to the copper parts, they should have been soaking an hour or two. A toothbrush and ketchup should clean much of the oxidation. It probably won’t be like new, but pretty darn good. Rinse, dry, and blow the parts.
That’s it, put it all back together.

NONONONO Shadow!!! Alcohol ruin ANY acrylic parts.

I have nerver seen anyone recommend this, running it in a loop, ever.

I just drain, toss tubing/replace with new. Disassemble all blocks and scrub with an old toothbrush.

Shadow, ask over at OC Forums and xtreme forums.

Ok, I did a little bit of digging on Tygon. If you already don't know, there are multiple types of Tygon. Including Chemical resistant ones : http://www.professionalplastics.com/TYGON2075
(Tygon® 2075 )

This type of Tygon is excellent against Alcohol and quite a few others: See:
http://74.125.95.132/search?q=cach [...] =firefox-a
(Look under "Relative Chemical Resistance Properties" )

I'm assuming I'm using this Tygon as my tubing hasn't gone to hell yet

(Also, this tubing (and quite a bit of other stuff) was given to me by an uncle that works at Northrop Grumman)

And yes, you guys are right DO NOT use Alcohol with other types of tubing. (I edited my OP to reflect this).

Also, Delrin (used in GTZ,etc) is also resistant to Alcohol
See: http://www.k-mac-plastics.net/data [...] _chart.htm