P.S.:
I know you asked for fairly realistic. I pull typically away from those requests if no reference material is provided.
So far it is certainly not defined, as a thick liquid is not a very precise project description. Besides, art direction will have another layer of qualities to be concerned about.
Here are some files, whereby I think, going with native Cinema 4D tools, the Cv2_r21_drs_20_ANri_01.c4d is the simplest and most elegant way to have a quick workflow for this effect.
The CV2_r21_drs_20_CLbr_01.c4d has more details.
Last but not least, the CV2_r21_drs_20_XAtf…c4d files are just very raw X-Particle sketches. (I have not included the cache, as those get quite large.)
As I mentioned, the Insydium forum is the place to go for that.
Files:
https://www.amazon.com/clouddrive/share/LRZ3nKoY9v2JzhyeQweGatHbdyG4Fj0lT5ucplBNzhN
Some extra information:
This is the closest I was able to find on Insydium.
https://insydium.ltd/support-home/video-manuals/x-particles-video-manual/dynamics/xpfluidfx/#1338
https://insydium.ltd/support-home/video-manuals/x-particles-video-manual/dynamics/xpfluidpbd-dynamics/#1321
On HelloLuxx, and I hope that is not considered advertisement: I guess with over nine hours of training should leave not so much left to learn, going by the shown results.
https://helloluxx.com/product/xpfluids-v01/
My best wishes for your project