Question about construction of Sigma 30mm and lubrication

I have seen threads on taking apart the lens to get at the inside of the focus ring.  No way I am going to try that as it seems quite involved.  That said, I was thinking of using a few drops of a silicone lube on the external joints and seeing if it will migrate into the mating surfaces while turning it.

Question is whether the lens is sealed and I don't risk the silicone migrating to lens or aperture surfaces?