Here's an idea for your "Why didn't I think of that?" file: A device that can quickly and affordably tell you if your hose lines are clean. As long as you have a supply of compressed air, it will work in your shop or at the track. And as long as both hose ends are loose, it can even be used to perform a clean-check on a hose that's still in the car.
Originally developed for use in the hydraulics industry, the device--known as the "Hose Hog"--is deceptively simple to be such a potentially useful tool. Constructed of an aluminum barrel with an air hose fitting on one end and screw-on adapters for several different AN sizes on the other, the Hose Hog is small enough to fit in any toolbox and can be carried to the track. The key is the foam pellets the Hog shoots through the hose to tell you if it's clean. Called "pigs," the foam pellets come in several sizes for use in a variety of hose diameters.
Clean As A ... Pig? To check a hose for cleanliness, both ends must be free, but fittings can still be attached. Using the correct AN adaptor, hand-tighten the Hose Hog to one end of the hose. The other end of the Hog must be attached to a compressed air line. Put an appropriately sized pig into the chamber of the Hog, close the chamber, and then crack the valve to the compressed air to shoot the pig through the hose. If the pig is clean after exiting the hose, you are good to go; if it picked up pieces of grit or other debris, you will know the hose isn't yet ready for installation.
What do you do then? Circle Track Technical Council member Keith Dorton follows this detailed hose cleaning procedure for new or used hoses. First, at the parts washer he completely flushes the hose internals with plenty of solvent (mineral spirits). Next, he'll cap/plug one end of the hose section, fill it partially with solvent, and then while sealing the other open end, shake and slosh the solvent back and forth through the hose section. After emptying the solvent out of the hose, he flushes the internals with copious amounts of clean, hot water. He'll then repeat the shake and slosh action, but this time with more clean, hot water. Finally, he uses the Hog to shoot a foam pig through the hose.