Yea, works great for the 'ROCK' players to clean their humbuckers up using the vol. Most use a 0.01micro farad but I find a 0.008 a little more subtle. It takes nothing away from the full vol sound. Its a nice little cheap mod I suggest to a lot of my customers.
Glyn
I'd second MrGlyn's suggestion of .008uF cap for treble bleed. Works nicely for most guitars with humbuckers and 500k pots. ( BTW, this item may be marked as .0082 or 8.2 n or 822 which all mean essentially the same. )
For single coil pickups, there are two kinds of treble bleed circuits often recommended ( google search) - both connected between the hot and centre terminals of the volume pot. One has a small cap and a resistor of a few hundred 'k' in parallel, and the other has cap and resistor in series. Surprisingly, both versions work, though they sound a bit different. The version with R and C in parallel seems to change the rotary loudness response of the pot more, which may benefit some samples of volume pot more than others. I usually try both and just go with what feels best on that particular instrument.