I have tried tween 80 for western blotting. It seems to work the same as tween 20 (I can't tell the difference).
Tween 20 is soluble in water, especially if you use hot water with stirring.
The critical micelle concentration of Tween 80 (polysorbate 80) in pure water is reported as 0.012 mM or 1.2M
tween 80 cause it has high absorption,with high concentration therefore high solubility
Anything if you seat your mind to it and have support from at least someone else :D