I'm currently working on the smog system, and wondering on the best approach to deal with rubber hoses that have become hard. I believe the hose pictured below (3932476, sorry about the bad iPhone picture) is the correct one that goes from the diverter valve across to the driver side AIR tube, so I'd like to keep and reuse it, however it is not very supple.
I've been reading about putting rubber parts in a pan of boiling water and wintergreen oil, which (by all accounts) has been successful in rejuvenating and softening rubber. Plus giving the shop an interesting aroma. I'm thinking about trying this on some scrap rubber hose off-cuts, but my main concern is with preserving the markings on the original hose. AFAIK, these are ink-stamped onto the hose and I'd hate to lose those in the process.
Any thoughts, tips or advice from those who have tried this?