Yup, the silicone also works fine.
I am a bit oldfashioned in that respect, I decided for gaskets

I have done this rocker lube mod on ALL my fourstrokes except for the radial (due to "logistical reasons", the tubing and the baffling result in a nightmare) and I am extremely happy with the results: soaking wet and brand sparkling clean rocker box and once the running surface of the cams has settled (that is where the initial change in valve lash comes from) no valve adjustments anymore.