Tokens invisible to all except the ones controlling them

I'm setting up an assassination mission conducted by two invisible PCs. Since the characters can't see one another, it would make sense for the players to be unable to see the other character's token as well - thus making it even more difficult for them to conduct their task without bumping into one another all the time. One solution I thought of was to make two copies of the map, then direct one player to one map, the other player to the other - but this of course is much too cumbersome. Could there be an easier way?

1) Use a transparent .png file for both characters' tokens. 2) Edit each token as follows:    a) On the Basic tab, set the Represents Character to the correct character sheet. If you don't need to refer to        sheet values, you can just set the Controlled By field to the proper player.    b) Still on the Basic tab, set Aura 1 to zero (0). Choose an appropriate different color for each token so you (the GM) can tell them apart.    c) Switch to the Advanced tab. Under Player Permissions, uncheck the See checkbox for Name, Bar 1, Bar 2, etc.    d) Still on the Advanced tab, check the Edit checkbox for Aura 1 (and any other fields you wish the controlling player to use).    e) Click the Save Changes button. Now you should see two colored spots representing each character. Each player can see their own token's aura, but not the other. Be prepared to swap them out for their regular tokens if they catch sight of one another.