What metaphors are used in Mutant Message Down Under by Marlo Morgan?

In Chapter Eight, Marlo describes a metaphoric purification, with the physical experience of being cleansed by the flying insects also serving as a metaphor for the spiritual experience of being cleansed of old ways of thought. The irony here is that the author tolerates the experience of being cleansed by the bugs by imagining herself back in a spa in New York, thus eliminating a potential level of additional spiritual meaning.