As I see it, it all boils down to a direct comparison. Here's how I did it.
I took my favorite Gillette Toggle out. Corked one edge of a Feather blade, running it lightly thru a cork about 4 times. Then I carefully put it in the toggle, noting which side of the toggle the corked edge was on.
On to the shave. Superlather, with a mix of Taylor's Sandlewood, and Tabac soap. Stirred up in my homemade Android scuttle, with a lovely Corian brush from Superior brushes.
Here's what I found. The toggle was set to 3. The corked side of the blade was noisier! More of a scritch scritch sound as it cut thru the whiskers. The other side was much quieter, and cut thru better. It was almost as if corking the blade dulled it, and thus the whiskers were being chopped off, while the uncorked edge was slicing them off. No cuts on either side of the blade, but that's more because a) the toggle is a smooth shaver, and b) I've been shaving DE for a while, and rarely cut myself anyway.
Conclusion: corking seems to dull the Feather, and certainly didn't improve the shave.
Next test: I'll try corking without cork, ie with styrofoam. It may be that you have to minimize the corking to get a benefit without dulling the blade.
I took my favorite Gillette Toggle out. Corked one edge of a Feather blade, running it lightly thru a cork about 4 times. Then I carefully put it in the toggle, noting which side of the toggle the corked edge was on.
On to the shave. Superlather, with a mix of Taylor's Sandlewood, and Tabac soap. Stirred up in my homemade Android scuttle, with a lovely Corian brush from Superior brushes.
Here's what I found. The toggle was set to 3. The corked side of the blade was noisier! More of a scritch scritch sound as it cut thru the whiskers. The other side was much quieter, and cut thru better. It was almost as if corking the blade dulled it, and thus the whiskers were being chopped off, while the uncorked edge was slicing them off. No cuts on either side of the blade, but that's more because a) the toggle is a smooth shaver, and b) I've been shaving DE for a while, and rarely cut myself anyway.
Conclusion: corking seems to dull the Feather, and certainly didn't improve the shave.
Next test: I'll try corking without cork, ie with styrofoam. It may be that you have to minimize the corking to get a benefit without dulling the blade.