Danielle, it's not a myth, just a design challenge.

When wood and water are intended to co-exist, one must make sure that a very durable water proof finish is used on the top, bottom and exposed edges of the butcher block. That includes the sink cutout, which when it's a very thick block like this one, should be recessed up into the block so it's not so far away from the user.

One must also finish plumbing fixture holes- so all cutouts should be made at the shop. Water proof finishes like our SatinSeal are sprayed on in a controlled environment- not site applied. They should be applied thin (ala furniture) not thick (ala polyurethane bar tops-... ick)

Traditional butcher block oil/wax treatments are beautiful, matte and capable of being used as a cutting board, but they are more like moisturizers than sealing finishes. They need to be re-applied to maintain their look and luster and protection. When folks forget to maintain their naturally treated kitchen wood products like cutting boards, spoons, butcher block etc., that is when you hear about moisture causing problems.

Natural Oil & Wax is best for islands without sinks. Wet zone countertops should be designed with a finish appropriate for it's use.