I'm not familiar with the exact odor produced by Holy H*** : ) but if it's anything like pet urine, you're right to be concerned. Assuming that some sort of protective urethane was used, sanding them down and restaining may work. If the stain has broken down at all because of age and the substance seeped into the wood it may not be that simple. I would find a furniture refinisher in your area and call and ask or even show them the chairs. It would be a shame to get rid of them - I hope you have some luck.