Device to hurt balls when erect?

Hi,

Is there any device to hurt balls when I get erection? Something like a chastity gage but adding pressure or stretch to the balls when I get a hard on. I have quite low hanging balls and probably need to use a ballstretcher to accomplish anything but I haven't been able to figured out what to add with a stretcher.

Edit: I don't know if it helps or makes things more difficult but I'm a grower.