Good reasoning but I think it would be on hell of a fan to pull say 1000mm head. Generally with pumps and fans I think it's easier to blow than suck.
You could run a simple test by making a U tube manometer and a transition piece (could be a plastic funnel or something cobbled together from card) and attach it to the fan, noting the difference between the two levels. That would be the depth to which you could immerse you inlet pipe.
It's not an original idea, but I use a pneumatic silencer attached to a compressor to de-water my hot oil. It certainly produces a much higher throughput of air than the venturi.
As a washing novice, I have to return my washed bio to the processor to dry it. I use the same method for this drying process.