You'd need some pretty heavy weights on your ankles, probably arms and weight as well, to provide force in place of the speed or thrusting you can't really engineer solo, else you'll probably just end up with a spike halfway through your guts, unable to get back off OR go any further down, and experience a very painful, regretful, less-than-fun end. And it won't be anywhere near as interesting a scene for whoever finds you. Remember to tilt your head back as well.

However I'd maybe suggest a vibrating buttplug instead.