How did it go?
The gas powered tiller should've worked on clay - but you would've had to water it down as much as possible AND mcGuyver up a harness so that you can actually hold it back as not to let it skip over te surface.
And yes - double up on the weed fabric - do not use a tarp - as the water cannot penetrate.
BTW - Aleve works great on aching muscles and back pains.