I have tried a couple without being very impressed, so I suppose you could put me down as a sceptic.
However, a most amiable and personable chap came to see me at the Midland Game Fair last autumn and asked if I would like to try a product called Microlon which is supposed to do all the things you describe; and even more, such as slicking the action and improving lock time and smoothness of trigger and bolt.
Have a look at www.microloneurope.co.uk
I am getting hopeful results with my Army and Navy black powder ball-and-shot gun, but that may be of little interest to Sporting Gun readers!
More useful, probably, will be the tests with my .270 once they are complete.
I might then go on to the .22 Hornet but that is currently so incredibly accurate that I absolutely will not touch it until I am certain of the result.
So stay tuned, just in case the Editor allows me to report on such arcane research.