I new these files were having a significant effect - for hose in doubt, look at my breast images in the gallery.
I have just bought a small CB6000s chastity cage - and the problem I have is that my penis is too small to fit in it comfortably. The head stays in the stem (not the bulb at the top) and even drops out at times, leaving the cage hanging on my testicles.
For those who think these files do not work, be careful, because over time, the changes are very significant.
gail.