Mukomet I think I know why you want your scrotum to hang lower..
I've heard many men brag of the fact that they have low hanging testicles. I think many men's testicles hang low at times, but as we all know they can draw up as well, especially at times of fear or extreme cold. My testicles hang very low at times and I admit I like the look of things when they do. When this happens it seems to exaggerate the size of the testicles and even gives the penis an overall larger appearance due to the fact the the scrotal sack is away from the penis, thus making it more visible and prominent looking.
As for a cream or anything to make the scrotum hang lower, well, I doubt there is such a thing. Some may use weights for this, and weights might actually work. If I were to bet you, I'd say if weights worked, they would only be effective for a short period of time, just like penis pumping.
The only other time I've noticed my testicles and scrotum hanging low was after an extremely satisying and large release of semen. They always retract though because that is the nature of your testicles, to stay near the body and be kept warm.
Just my opinion..