I occasionally do things like that on a lower scale, for example I have a maid in my game that is lazy and squeamish and always complains when she has to take the trash out, and right now I'm trying to find a boyfriend for my unflirty loner. Whether or not this is actually fun depends on the sim and the player, but it is definitely challenging, to say the least. :D
Another idea would be to give a squeamish sim a nature-related aspiration like Curator or Outdoor Enthusiast, good luck making them dig in the dirt and collect insects all the time. >:)
