IPM - Hospitality Industry

All - I am working a five-star resort on a small island. What is used for landscaping is nearly all least toxic (the one that isn't - we think we can replace). However, in terms of guest rooms, we have talked to other properties, as well as companies, and the consensus is that the least toxic chemicals simply do not work. As a property that makes its living on occupancy, trying other least toxic methods and documenting those is a HUGE risk that could have long-term detrimental affects. Would the fact others, on this very small island with the same flora/fauna, have found the ineffective be sufficient. Otherwise, 100% implementation could put the viability of the business on the line. Thank you.