I never tried sealing paracord before but if the knife was going to get that messy I wouldn't bother wrapping the handle.
BUT since we are talking about you and not me I would suggest taking a scrap piece of paracord and wrap it around a stick/piece of wood, then seal the paracord with whatever sealant you have then get the paracord all messy and after it dries or you rinse it off see what happens paracord and to the stick underneath the paracord wrap.
My point is with using a stick/piece of wood is to test if you will get a lot of staining underneath the paracord wrap. Because later on that could start to stink, rust, etc.
BUT since we are talking about you and not me I would suggest taking a scrap piece of paracord and wrap it around a stick/piece of wood, then seal the paracord with whatever sealant you have then get the paracord all messy and after it dries or you rinse it off see what happens paracord and to the stick underneath the paracord wrap.
My point is with using a stick/piece of wood is to test if you will get a lot of staining underneath the paracord wrap. Because later on that could start to stink, rust, etc.