Do you need dry weather for Henslar's pot? Or is it safe except in extreme conditions?

Also, it's the Craven winch meet this week, does anyone know if Henslar's is rigged?

As far as I am aware the only dodgy section is the duck just before the first pitch, it can become impassable but I'm only aware of this happening in extream conditions, don't know about the rest. The Craven winch is running until the 27th of August, they don't rig entrances for the caving community so it is unlikely you will find it rigged.