As much as I agree that new rubbers are the ants pants, we should all be aware that once a bit of gas gets on them a few times, they're screwed.
I was surprised at how quickly a new set of OEM inlet rubbers went hard on my K2 engine, so I'm not prepared to laugh off all of the crackpot "rejuvinating" scams just yet.
I tried the armorall in the bag trick for several months and it did nothing at all but made them slippery, but I'm hoping someone out there will come up with something soon, I've got 10 or 12 sets of hard rubbers I'd like to "recycle" one day..................