Not corrosive, but it is sticky. I have ruined a gauge or two with the RimGuard. You need to be careful, get the valve stem at "12 o'clock", let out a little air to hopefully purge any remaining 'juice' out of the valve stem and hopefully be able to check 'just air'. I had one tire that seemed to be just a bit overfull and it took a few times to get 'just air' out of the valve stem when checking pressure. It didn't take much of the beet juice to muck up the pressure gauge.
But, I don't think you would do any better with a gauge designed for the CaCl filled tires. Sticky is sticky.
Wxman