I've always stayed away from wood bowls for that reason and I do have one but don't use it anymore. I guess if its well sealed it should be OK but water soaking in it is never good but then again I don't know that these wood bowls are made to last a long time.
As far a lather goes I have always lathered directly on my face and thats fine but recently acquired a G-3 scuttle and I have to say the quality of the lather is much higher doing it that way. I think the difference is great enough to justify the purchase, or at least that's what I told my wife.