Here's a couple photos of how I did it. Just get some large pan to act as a catch basin and use waterproof tarp or plastic sheeting as a giant funnel, with the sump sitting in the lowest point of the sheeting, inside the pan. Use binder clips to hold the plastic sheet to the body and to maintain the downward funnelling of the liquid.
Here is an underside view. I used some wire coathangers to hold the sprayer in various positions. The warmer the liquid is, the faster it works. Hot summer weather is best but you can also use a small fishpond heater to keep the liquid temperature up. 80 degrees or more works great.
