Going "Full Swedish" = "Getting awesome"

Lately, we have been using the term "Full Swedish" or asking, "Should we go 'Full Swedish'?"  Basically, that question or statement means that we are doing things the local way.  For instance, Jon and I walked into our local, beautiful, nature-ish swimming pool and there was a sign (in Swedish) that said,

"Note: Parents, all children must wear bathing suits in the small and large pools for health."

Why is that written in bold letters on a white board as soon as you enter the pool?