Yes, but only with the immersible probe! That one is specifically designed to be water resistant (at least) so it can be entirely submerged without damaging. The others will allow liquid to damage the wiring where the probe meets the cable, so you want to avoid getting that part wet.
ThermoWorks also has 12" probes which, while they are not waterproof, are long enough that you can still measure fairly deep in your grain bed.