Johnson Controls A419 Probe

I just bought a Johnson Controls A419 controller with a carboy heater and thermowell from northern brewer for brewing in my cold basement. Here's the setup
I need to use a blow-off tube in the beginning of the fermentation and therefore cannot use the thermowell included in the kit. Is the probe included with the A419 waterproof / food safe? I was considering running the probe up the blow-off tube and submersing it in the beer during the blow off stage if it were possible. Has anyone heard of this or tried it before?

I don't know if the A419 is waterproof, but looking at mine it doesn't seem to be as the probe tip is simply crimped to the wire lead. It appears to be stainless, but not sure about that. Why not just run a smaller blow off tube and connect it to the hole in the stopper where the airlock is supposed to attach? The smaller blow off tubes are more prone to plugging, but it's also fairly easy to check them and clean as needed for the first few days of the ferment when it's most active. Once it slows, you can replace the blow off with a dreaded air lock.