Oleophilic (i.e., oil attracting) carpet fibers (e.g., polyester, olefin) will absorb oily soils over time more than nylon, leaving a yellowish look on traffic areas that cannot be removed with normal cleaning. However, with proper professional pretreatment and with maximum application of the principles of cleaning, oily oils can more effectively be removed from Oleophilic carpet fibers.
Should sanded grout be used in a “polish natural stone installation”? The answer is NO. Because either during installation, daily maintenance or during professional cleaning or restoration if any of the sand in grout comes out and gets rubbed or worked on the polish surface it will scratch it.