Nonsense. The comfort comes from proper fit and spreading the recoil throughout the palm, not silly rubber "cushion". Recoil should be absorbed by the hands, wrists and elbows. No, they don't get slippery and they don't rub the skin off you hands the way rubber does. Rubber is a crutch, a bandaid for poorly fitting grips.
Craig is exactly correct. All of my revolvers get Nill grips because they make models that fit my hand properly.
Look at it this way. If you take a rubber mallet and slap your hand a little bit, it would probably hurt a little less than using a a wooden or metal mallet. The rubber of the mallet, and the grip, gives a little and thus stings a bit less. However, if you put the mallet of any kind in your hand and then push with an equal force, it won't hurt at all. That's Craig's point. The rubber grips are giving a little and transferring less recoil to your hand when they rattle around in your hand. However a wood grip that is properly fitted to your hand won't rattle around at all, it just pushes into your hands rather than slapping you. There is no impact to your hand to be absorbed. The recoil is transferred to your arms as it is meant to be.
Here's an example. I had Altamont grips on my 686+. They were way to thin for my hands. So, I got some Badger finger grooved grips. They left the backstrap open as many grips for an L frame do. Well, in order to get a firm grip and have a proper trigger reach, the backstrap was not firmly planted in the web of my hand. As a result, when I pulled the trigger, the grip slapped my hand pretty hard and was no fun to shoot, and follow up shots were really slow.
Then I put a closed blackstrap walnut grip on. The web of my hand sits firmly on the grip, my trigger reach is appropriate, and I'm able to keep a firm grip on the gun. As a result, the gun doesn't hurt me anymore, and I can shoot the gun much faster.
On the other side of it, my 460 mag wears a Hogue Deceleratir grip as all stock X-frames come with. I shoot that gun well because the grip happens to fit me well. It may be the same with your Alaskan. I doubt though if I were to put wood grips properly fitted to my hand on my 460 that I'd feel much difference.
It isn't about using a material that absorbed the impact between your hand and the grip or disperses recoil energy, it's about having a grip that doesn't move around in your hand so that recoil is transferred properly to your arms. When grips really fit you well, the material doesn't need to be terribly pliable. It just needs to be flexible enough to avoid cracking from the vibration of the gun, like wood.
As far as slippery from hand sweat, that's a negatory. With a good firm grip, finely finished wood is very easily held onto. I prefer stippled grips, but I have boney fingers so it helps me keep the gun in place.