ok, since 100% of what i've come up with has already been thought of, i'm pretty sure that someone has come up with this already, but here it goes.
i'm thinking that maybe the oscillating stretch is a bit of a wrong name for it...but it sounded appropriate at the time.
What i liken the stretch to is a hand drill. If you've ever used a hand drill, you will know what i'm talking about, if you haven't, here's what one looks like
Grab the head like you would for any stretch, and stretch straight out. Using your other hand, make an "OK" sign around your mid to lower shaft. Start doing low radius (1-2 inch radius) rotary cranks, while at the same time pushing the opposite way with your shaft hand. Its essentially constant fulcrum rotary stretching, but since its skin on skin, there's no shaft irritation.
For me, at least, i've been getting constant lig pops with every crank, and really really sore ligs in the shaft.