[NaOH]

Materials:

-RTV silicone
-water
-a jar (dont use beaker because the silicone will stick to it use an inexpensive mayo jar ect.)
-a stiring device (I used a pencil)
Alway use safty gogles, if the acetic acid get into your eye it will hurt.

How to make it:

-Pour some RTV silicone onto the jar
-Pour some water till it covers the silicone
-Stir it
-Leave it there for a while
-Get a storing container and pour in it the water

How does it workk:

The RTV silicone releases acetic acid in gas form when curing. When you put the silicone in water the acetic acid will get into the water.

[billnotgatez]

What else does it release in water