Well. It doesn't seem like it's a stretching device, more of a anti-turtle device.
For night: To give it more of a stretch you would look @ the caps and straps that they sell w/ them. You apply the sleeve on the cap and the cap to the strap, then roll down the sleeve.
For day: The above or using weights along side the sleeves.
It would make a nice starting grounds though.
You might look @ the caps that they sell. It works very similar to how the vac-hanger is. Doesn't seem like they're vac system uses a pump, mainly uses the vacuum it creates just from a cap/sleeve combo. Google the vac hanger and see how it's applied, this will give you a sense of what I'm trying to explain. The
phallosan would work very similar, except there is too much give w/ the condoms, so you must rely on the internal vac system it comes with.