How to invite over an alien that used to be a pollination technician?

I do have one idea. Find the sim you want to invite over, but can't, also find another sim and move the two in together. Then merge the one in with your sim, while leaving the other one behind. Then do what ever it is you want for them to do. Then afterwards, go back into Manage Worlds, and move the alien back in with that other sim you had first merged. Now why said all that, is so you don't get an addition 20,000 semolians added to your sim's family household funds, but you can still have your sim enjoy the other sim's company.