Have seen those for some time now. Whenever I apply the whetstones/oil on steel swords, they are immediately reflected by changes in the Character screen. For example,
Whirl -> Damage increased.
Specter oil -> Damage vs wraith +20%.

But when I apply them to my silver swords, the changes described above are not seen in the Character screen. Plus, my damage output as seen in combat logs are not changed despite the applied enhancement.

Does anyone experience the same thing? Is this a design choice?

Anyone? It is pretty easy to test this.
a) Hit an enemy a few times, get a feel of the range of damage you deal from combat log.
b) Apply say a whetstone on your silver sword, then hit the same type of enemy and observe the damage on the combat log.

I'll check it tonight to see if I get the same results.

Any new findings?

I tried it with 2 or 3 playthroughs and they all have this issue. Apparently no one else does.

By the way can you test it to see if yours work?

All I know is if I applied any enhancement to my sword, saved the game, then reloaded, the enhancement was used but its effect on my sword were gone. I learned to apply them only after I reloaded a game.

Is this with a silver sword or steel sword? I haven't tested with the save and load but just applying them to silver swords have no effect other than displaying the icon and timer.

Both swords. Whether I do a quick save or regular save. If I apply an enhancement, save the game, exit to menu, then reload, the effect of the enhancement is gone, but it's been used anyway and is missing from my inventory.

I just killed a couple of specters in Claws of Madness. First try without specter oil, second try with specter oil. Damage range (Aerondight dmg12-19, 1 fire 1 moon rune) without oil from 17-25, with oil 15-22... that's not very meaningful. With specters, it's also a little hard to keep eyes on the combat log, make screenshots and stay alive for long enough to get a few licks in. ;)

But at first glance it doesn't look like it makes a difference. I guess I'll conduct another experiment on those two wraiths with a different oil now...

~°~

Falka's Blood gets hits from 16-25. And there have been spinning slashes, I'm guessing they do more damage on their own. So nope, seems not to work at all.

~°~

I now have learned, that I can kill a specter with a scoop with "minimal damage" (not even a number), oil doesn't do a thing. I have learned, that a broom does the same damage against specters as a robust long sword, which is 6. With or without oil.

And why did I need 20 traps on easy setting the first time around and on hard I beat them to death with a spoon?? Did the patch nerf the difficulty that much or is it me? Seriously sad that I don't have a shovel with me right now, because "beat you to death with a shovel" is so much more classy *g*.

No, specter is probably a bad choice as your test subject. They attack faster than you (thanks to simpler attack animation) and I think they have riposte (mentioned in Character -> Knowledge). But it seems like the oils do not work for you as well, because if the specter oil works you would probably get a range like 21-30 ish. Well both robust long sword and scoop are not effective against monsters, so the gap in their damage is probably reduced by a fair bit, making them seeming not too different vs wraiths.

Well you mentioned that with the wraiths attacking so quickly you are having difficulty paying attention to the combat log hence my suggestion about not using them as test subjects. If you have some whetstones, you can probably test it against endregas - they don't leap, they don't riposte, and they have way lower damage than wraiths.
Never played with FCR, but without specter oil you can't damage a specter?
Well to be fair, it only affects one skill in Alchemy tree although I must admit not having being able to get that extra +50% vs wraith (fully upgraded oil specialization) is a downer.

As I said, I especially wanted to test the specter oil. So it was worth it to die a couple times while testing. ;)

If you're ever gonna play TW again, do yourself the favor and give FCR a try! No need to choose insane difficulty right away, as the easiest setting is already harder than vanilla hard. But it completely changes just about EVERYTHING, you'll get a whole new game out of it. New sword models, new talents, new sign - Heliotrope was originally Flash's idea. New rules like "you need specter oil, because your attack is lower than their defense, if you don't use it". There's a big fat excel sheet included with all the details. Fights are a lot faster, vitality and stamina much less (no more 500 vit and being untouchable in the end, I think 100 is max). You actually eat food and drink milk and water for the slightly increased vit and sta regen. And much more. A lot closer to the books. I really got used to the FCR playing style and since Flash was somehow involved in TW2 (dunno how exactly), I had hoped that we get at least a hard difficulty with similar combat mechanics.

I think we speak of different aspects. I mean alchemy generally, even without specialisation it should make a difference. Like in FCR, where you can NOT survive without doing at least some alchemy. In TW vanilla on easy or medium, you could got through the whole game withough brewing one potion - TW2 feels like that, even on hard. Insane might be better, but I won't start an insane run before someone mods out the permadeath and adds a different punishment for dying. One that hurts, but doesn't end the game. I know there is a tool, with which you can restore dead saves, but then you get no punishment at all and that's too easy for insane. ;)

Nope. Same here, when i apply it on silver sword i have timer and icon but no effect in character screen.

There's the combat action screen where it mentioned Geralt deals how many damage to enemy. Was there any difference before and after applying oils and whetstone to silver sword?

If there aren't then i concur it's bugged. Should be reported to CDPR if it's true.