The thing that seems to most consistently confer musk descriptors is having a horsecock, honestly.
Fluid types are interchangeable, meaning any of them work as the given fluid if edited to the relevant value, and don't have any flags as far as I can tell. Hence, stuff like this is mostly up to headcanon.
In terms of pure viscosity: blueberry yogurt (only available as a cum type through console commands) honey, sugar (described as 'icing', can be cum or girlcum without console commands), and pure chocolate cum (only available without console commands for dicks) are probably the thickest. Everything else is either milk (low viscosity), the usual kind, syrup (thinner than honey), oil, or not really described in detail. Gabilani cum is specifically oily/semi-transparent oil, iirc.