I have never seen a Biolet toilet before, but looking at the website with some suspicion I would save a few thousand dollars and go with a good quality camping toilet instead, like this one and spend the difference on a meal out in DC. Empty it after every party. One of these camping toilets kept me and my wife going for a week when our main toilet was out of action for a bathroom remodel. For one night it will not smell, after seven days it definitely will. I trust your parties do not last that long! A good camping toilet will flush, not smell (for several days) and will keep the waste out of sight through the neat use of a plastic flapper. They even sell (degradeable) toilet paper that should be used with these as well as deodorising chemicals.
Good camping toilets work great but emptying them is not that pleasant. I emptied mine slowly down my household toilet (not too quick since you would not want to block it). Again doing this after one night would be better than after a week (I needed a face mask). I simply cannot believe that emptying a Biolet toilet would be that nice either, and I would not be willing to put its by-product on my garden. If you go with the camping toilet, you'll see what I mean!