[I]n terms of injecting dye mixed with poison into the horn (also discussed in our 'thorny issues'), it has been proven that rhino horn is not porous and that a liquid mix does not diffuse throughout the horn. In other words, the poison/dye mix remains in the drilled holes, making it relatively easy to remove and “detox” the horn if it is, indeed, to be consumed. Any remaining external discolouration can be sanded off. And tellingly, dyeing/poisoning Sabi Sands’ rhinos’ horns did not prevent animals from subsequently being poached.
https://www.savetherhino.org/rhino_info/thorny_issues/dyeing...
[I]n terms of injecting dye mixed with poison into the horn (also discussed in our 'thorny issues'), it has been proven that rhino horn is not porous and that a liquid mix does not diffuse throughout the horn. In other words, the poison/dye mix remains in the drilled holes, making it relatively easy to remove and “detox” the horn if it is, indeed, to be consumed. Any remaining external discolouration can be sanded off. And tellingly, dyeing/poisoning Sabi Sands’ rhinos’ horns did not prevent animals from subsequently being poached.