My personal experience about creams or skin care products would suggest Shea Butter.
Heck, in my country there's a shea butter product labeled "ball wax" (direct translation), to be used on your balls and dick. But really, just get an organic tub of shea butter. Really helped my skin overall, I need to get more of it actually.
A great product on many body parts, even your face and it's decent for hair as well in moderation.
I don't know anything about dermal fillers, but Black Seed Oil is supposed to help with girth department. This can be taken internally and applied externally. No real results in, I found it nice in use, perhaps some more vascularity due to the oil. (Just external usage!)
I think I read about that Man1 Oil longer time ago and got to the ingredients list. And now I checked it again from the Amazon link customer picture; just doesn't impress me that much.
I'd rather get the Shea Butter by itself and maybe mix it essential oils. (I actually made a deodorant this way, it has worked great!)
Other possibility from non-comedogenic oils would be hemp seed oil. I've used that one succesfully as well, but shea butter has very mild smell compared to hemp seed oil.
And one more thing about Shea Butter or hemp seed oil; way more natural (of course source must be put into consideration) than this Man1 Oil is, according to the ingredients list.
All the best, keep on exercising!