For start, tapeworm treatment for humans is tablets. Very easy.
And cats are naturally clean animals. They *usually* don't spread that kind of dirt around. I say usually, because they can still accidentally step in it, whatever they're age. :-/
One of my cats has always been accurate in the tray, which means she goes exactly where she digs and covers it all neatly. Even from 10 weeks. The other one was more spatially challenged: she had trouble matching the location of the covering action with the location of what needed covering. I mention this because I'm given to believe it's unusual: all the cats my parents have ever had have been pretty good on that score. So.