Likely the build up of detergent and grease from the kitchen sink line over a number of years.

They will also remove any affected materials that cannot be treated with detergent/water solution.Once the remediation work is completed, have the mold inspection company come back out for a re-test. 

Regardless of detergent type or "rinsing" agent. 

Dawn or some other dish detergent.

Gallon of bleach water with a small bottle of dish detergent, put into a pump sprayer.The bleach kills the mold and the dish detergent keeps the bleach attached to the walls or beams if you have to remove the drywall.We have used this system over and over, both in NOLA and in FL, where we do the work then call a remediation company to test.  

It is basically a really strong detergent. 

There's a washer/dryer with detergent in every house. 

Things to think about:Transient occupancy taxes, inspection fees, business licensing fee, etcUtility costs, which will be much higher than average bc people use your property like a hotelLaundry costsConsumables (tp, paper towels, shampoo, soap, dish detergent, sponges, cleaning supplies, etc)

All supplies such as towels, linens, soap, detergent, t.p. are stocked.

Claimants who receivedsettlement may not claim again and no additional replacement floors will be supplied.x Alternatively, a refund of up to 100% of the original cost of the material (the percentage of the originalcost refundable depends on the amount of time elapsed since the date of purchase: within 1-2 years -100%; within 3-5 years - 70%; within 5-20 years 50%.x No representative, employee, or agent of STAINMASTER™, Lowe’s or their affiliates are authorized tomodify or change the limited warranty as stated here in.Warranty Limitations:x This warranty is not transferablex Manufacturing defect must be reported within 3 months from the date of purchasex This warranty covers only properly installed and maintained floors, according to the instructions on thepackage.x This product is sold as a Do-It-Yourself (D.I.Y.) product and therefore professional labor costs forresidential installations are not covered under this warranty.x The manufacturer excludes and will not pay for any consequential or incidental damages under this limitedwarranty.x The manufacturer will not pay for the loss of time, inconvenience or other incidental expenses incurredduring the installation and the subsequent removal and/or reinstallation of affected material.x This warranty does not cover the exclusions indicated on the package.x The manufacturer reserves the right of final judgement and may refuse claims in certain instances.x The manufacturer reserves the right to modify or withdraw the warranty at any time.x The manufacturer reserves the right to inspect any flooring claimed to be defective in the installedenvironment, either by a company representative or independent 3rd-party inspection service.This warranty does not include the following:x Improper installation or product not installed according to Novalis installation guidelines and accepted industrystandards.x Flooring installed in areas not suitable for solid vinyl plank or tile.x Lack of maintenance or improper maintenance such as dulling by soaps, detergents, harsh chemicals, dressings,one-step cleaners or wax.x Damaged by narrow tipped heels, vacuum cleaners, burns, cuts, scratches, gouges and indentations caused byrolling loads, caster wheels, furniture and chairs without proper floor protectors and furniture rests and cuts bysharp objects.x Damages caused by burns, flooding, fires and other disasters.x Staining or changes in color caused by dyes tracked from carpet, fertilizers, coal, tar, driveway sealers, oildrippings or other similar materials; faded or discolored by sunlight or heat generationx Stains, fading, discoloration or moisture problems due to use of rubber or rubber-backed mats.x Problems or damage due to moisture and/or alkalinity in sub floor; discoloration or bond release fromhydrostatic pressure or excessive moisture caused by flooding, plumbing and appliance leaks and water leakagefrom doors.x Mold and mildew growth caused by excessive moisture.x Installed over unstable, unsuitable, or improperly prepared sub floors, wet/cold floor and/or radiant-heatedfloor in excess of 85⁰F.x Different from samples or printed material in shade, color or embossing.