I understand that the usual single-component RTV acetic-cure silicone cures by hydrolyzing silyl acetates, consuming water in the process, normally from the air (and producing acetic acid). That’s why it doesn’t cure in the tube and why it takes a long time to cure if you spread it too thick.
It occurred to me that this affords a simple silicone 3-D printing process: first, you make a big block of the liquid silicone in a cup, and let it skin over the top. Then, you insert a hypodermic into the silicone through the skin to the bottom of the cup, withdrawing the needle while injecting water. By repeating this process you can create water bubbles at different locations in the silicone mass, close enough together that the silicone around them will join into a continuous object when enough of it is cured by the water. Once the curing has proceeded to this point, you must remove the uncured silicone; Smooth-On recommends acetone or mineral spirits (naphtha or Zippo fuel), while others report that ethanol works too, and some even report success with ordinary aqueous detergents (Dow Corning DS-1000 Aqueous Silicone Cleaner is such a formulation). GE recommends mineral spirits or "rubbing alcohol" (probably 70% isopropanol).
This kind of needle injection of reagent into a gel or viscous liquid is much more broadly applicable. You can thus inject dyes into jello, for example (according to Soonish); or you can inject carbon dioxide or calcium chloride into a green body of quartz sand lightly moistened with soluble silicates, which will harden the silicates immediately; or you can inject cold plasma (of air, for example) into a wide variety of powders to activate the surfaces of powder particles to get them to clump together;