There's no general way to untaint my vars, as they aren't supposed to contain general values. To make sense, each plausibility check needs to be done individually as to what needs to be checked for, thereby untainting the variable. Simplifying that much doesn't make sense in real life.

Don't blame me for not getting the joke this time =)
I got it, will use the unicorn's horn...

Cheers, Sören