The following was an excerpt from the Rogue Trader Ork book. It speaks of Drops (where the orks do their business.) and Squigs, and Snotlings.
The Squigs are grown in the drops or cesspits, and are raised by the Snotlings, until they are big enough to fulfill what ever role they are needed. (Which we will take a look at in future articles.)
So, what have we learned? Squigs come from poop, are raised by weakling, cowardly orkoids known as Snotlings, and that there are lots of Squigs. Lets actually take a look at how Squigs affect the orks. Well, you name it, (or the ork equivalent) part of it probably came from a squig. Tires for example. Sure, some are looted, and even the the books only ever mention oil squigs, however I am sure there are tar squigs that secrete a thick tar like fluid from their snouts when squeezed. And the orks use these tar squigs to make tires, and other rubbers. Like the rubber that they use in their hoses and such. Somehow they probably refine it. (With much trial and error, mostly error, and no doubt some Gretchin limbs flying in all directions.) Then they use it in the items they need rubber for.
Speculation is fun.
Even though this post is kinda lax, and I am tired, I will say that the bottom line is this, Squigs are a necessary part of orkish society, and we will look at the different types in the coming weeks.