A surprisingly-nuanced and detailed piece from Gym Climber:
https://www.gymclimber.com/can-liquid-chalk-protect-climbers-from-coronavir...
Alcohol percentage isn't the only issue, it appears; unbound water (not absorbed by the chalk) is also needed, and it's less effective if applied to dirty hands.
So: might be helpful, but not to be relied on as equivalent to regular hand sanitizer (which is itself less effective than hand-washing).