It's about colons and spaces - or rather......
Nature being what it is, there are a lot of spaces that exist in the wild, perfectly naturally. These could be things as complex as valleys formed by glaciation, or the space between Richard's ears where cricket knowledge would reside if it wasn't for nonsense like first-chance averages and Stuart MacGill.
Many of these natural spaces are formed by water over millions of years - liquid or frozen - but of late man has intervened and speeded up the process.
See what you can do harnessing the power of water by damming - you can use it to drive turbines (water occupies the spaces on one side of a rotor, causing it to spin, rotating a coil inside enormous magnets - or is it the other way around?) and generate electricity.
The water after it has passed through the turbines can then be used to water crops in fields (another form of space - often dry). You see where this is leading?
.....colons and watering dry empty spaces.
The poster is obviously alluding to
honi being a fan of colonic irrigation.
/aren't we all?