Or would informing them sooner could turn the relationship more "toxic" sooner and invite more troubles?

Probably the most irritating thing for me, which may also be the best thing, about Hawaii real estate or Hawaii in general from the angle of business, is termed "Hawaiian Time".  

A few key points. 1) this stuff is toxic and can hurt you or worse (be 100% sure you buy respirator and have fresh air blown in) and only do it in unoccupied unit. maybe worst (toxic) stuff I have worked with residentially... bugs were dropping dead by the window...2) no it is not forever permanent--but what it is. 3) prep, prep, and more prep. 4) I would use it on a surround that gets some water splash--not where it gets constant water or submersed (like actual tub, need heavy duty stuff there). 5) follow all instructions and research well....cheap (25-30 bucks + roller)--but a lot of prep labor. it would make the surround look nice enough for the sale and/or get you through a few tenancies on a shoestring until you or someone replaces it.

Nobody wants to see this market turn in to something toxic, and if you read PandoDaily there's been some good reporting on worst-case-scenarios just in the last week.

I know I get super irritated when I call a customer service number and get automated menus when I really want to speak to a person and have them solve my problem.

It's natural, awesome stuff to kill pests and isn't toxic.

I heavily empathize with her concerns but it is something that people need to maintain their logic about.www.the-scientist.com%2Fnews-opinion%2Fhow-toxic-is-the-worlds-most-popular-herbicide-roundup-30308

Toxic black mold is the worst.

First thing is to find the source of the smell; here's a couple articles on where to start and how to clean it:https://molekule.com/blog/11-common-places-check-mold-home/http://www.startribune.com/finding-source-of-mold-can-be-difficult/47941212/Not all mold is "toxic." 

Some view them as toxic while others see a goldmine.