@planch -- Oh, it's totally doable. A home body polish is going to be a little different than a spa one just because you have different equipment, but you can still have a really nice experience.
First, set a nice mood for yourself with some candles and soothing music, just like you'd expect to find at a spa. I think it's not nearly as fun to do beauty treatments at home if you don't make the atmosphere.
Next, you take your polish and a back scrubbing brush or loofa. I'd recommend that you take a brief shower beforehand, since polish applies better to damp skin.
Then, you take a gob of polish -- don't skimp! -- and begin to rub it wherever you feel like you need a little skin TLC. Hotspots are the feet, knees and elbows, since the skin tends to be a little rougher there.
Also, be careful not to be too rough, especially on sensitive parts of your body. This is meant to be an enjoyable experience.
After you've done all the areas you can reach, then put some scrub on the back brush or loofa and do your back. Again, be careful of sensitive areas.
Then rinse off in a nice bath or shower, moisturize, and enjoy your fabulously baby soft skin!
Oh, and if you like trillium, you should give organic strawberry body polish a try -- definitely one of my all time favorites!