Issues with homemade aquarium decorations?

We got an aquarium several weeks ago and I started to really like it. I wanted to make some decorations/shelters for it and I did a bit of research on multiple sites. ALL of them said that you can use basalt or granite rocks with fish safe silicone. And that's exactly what I did. I took some basalt rocks(like the ones on railroad tracks, unused of course), boiled them, let them dry and glued them together with aquarium silicone into a few shelters or simpler decorations. I built them step by step, let them dry etc. As the silicone smells something like vinegar, and some strands are left by the rocks(i will clean most of them) I still am concerned about its safety(on it package it states CLEARLY that its made for aquariums, its non toxic and may emit acetic acid when it dries). It is AquaSil Transparent Silicone from JBL. Are these shelters safe to use?