I'd try really hard to get the water out. The bread trick may solve your immediate soldering problem but it's always caused me a future problem. Clogging up some small orifice, air bleed, inlet to temperature/pressure gauge, etc. I've yet to see a case where an air compressor, shop vacuum (suck or blow) or a leaf blower couldn't get the water out. It may make a mess but a leaf blower directed through a funnel into a pipe will blow out a lot of water in a hurry. Leave it run long enough and it will dry the inside of the pipe too. This eliminates steam when soldering which will sometime pressurize the pipe blowing the molten solder out preventing a reliable joint.