You’d smell ass

No wonder aliens haven’t visited earth yet.

I mean it would really depend on a couple of factors. For one, a common way of manipulating voodoo dolls is by using pins and filling the doll with hair (in this case your own) and often poisonous and sometimes intensely hallucinogenic herbs. Some of these herbs are known to even be transdermally active. If these pins were to introduce these toxins into your bloodstream then I would say no, standing up is not in your cards.

I would think that the act of sitting on the voodoo doll would even compound the likelihood of a large dose of toxic herbs getting into your bloodstream so… You might be down for a few days to a little more than a week at worst if you survive.

Another thing to consider is that if the doll has no pins in it then which position is it in when you sit on it? As you’re not manipulating it with pins or even something conductive (which is an important factor in witchcraft), the effects are likely to be muted. Say you sit only on its head, you are likely to get a little bit of a headache. If it’s folded over and crumpled you might get back pains. I’m sure you get the idea.

So in this scenario I would have to say that it depends on the positioning of the doll and your resilience to the metaphysical.