I would recommend it as the product of choice for many reasons, but it surely won't hurt the snake for the short term. I like to use something that holds humidity a little more easily than calci-sand.... it usually clumps and turns rock hard when exposed to higher humidity that copperheads enjoy. I would give the snake a humidity box to aid in respiration and shedding until you switch back to the normal substrate...
I use my own mixtuer of peat, sawmill fines (big saw dust, sort of) and pine shavings to make a mixture that does everything I want it to do... for species that like it a little drier, I work some sand into the mixture and add less water...
Tom
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"Seek first to understand, then to be understood"