Yeah pretty much what Lulu said. If you're using the toilet for WASTE and not composting (which takes a LONG time for humanure to safely compost, try 2 years if done right) then no need to separate. Unless you have it sitting there for long periods. Urine with crap will smell FAST. If you're dumping once a day, using saw dust, I wouldn't bother separating. If not, then ya might want to put a cute little pee shoot or bowl in that drains to a tank. Hard to do with kids around so I've found. They're not used to holding the flow.