so your original question was "Can I use a oil in the steering knuckle ?" ......and apparently you already new the answer to your question. 
So good luck trying to find This OEM Toyota "semi fluid grease" to put in your axle.
Yep You aint kidding it took me a solid month to track this stuff down, studying grease, consulting with grease and oil specialists,
So yep after I found it only able to get in bulk I figered others would want to know about this stuff and use it,
So then posted On Ih8mud, only to find that it is a extension of a Toyota dealership and they werent having it,
This has been a couple years in the process,, Yes only took a month to find it another one to get it shipped and in the shop
But going on 2 years of wrangling the Rixatus effect caused by Toyota sales,,,
Well its coming down If the Crawlers can step up
