Hondaman: please post your results!! this could be an addendum to your book!!!
Results: EXCELLENT. I had some original 1971 hoses that were so hard theey felt like aluminum (been stored 27 years since I took them off my bike). It took 5 days of soaking: now they are like brand new, and it removed the "signature" creases that were found around the spigots at the head, to boot. Then I took the air horns from the airbox and soaked them 2 days (similar condition to start with, and very shrunken in diameter). When I took them out, they were larger OD than the new ones I have from Honda. About 3 days later, they shrunk to be the exact same OD as these brand new ones, and are slightly MORE flexible than these new ones. Once installed into the airbox, they are a perfect seal again.
I now have soaked 5 complete sets of hoses and 3 sets of air horns, will next be reviving a K7 set (since some of these are no longer available, and I'm building a fancy cafe' for someone). I completely recommend it! If you have a set that needs soaking, I could probably drop them into this can for a week for you for a few bucks: some of the "stuff" soaks into the rubber and some apparently evaporates, even through the plastic lid of the can, so I have used up 2/3 of the "stuff". I can get more, but would need to charge something to cost those costs...
Maybe, $10 to soak your old ones for you? Plus Priority Mail shipping in their Flat Rate box, that would be $20 overall cost for some good hoses!