We have found using microfiber face cloths under a flat telescopic mop frame to be the best method for applying sealers or polish to vinyl type floors as you will always achieve a perfect smooth finish without any application marks, many years ago we used to apply them with string cotton mops but always found that these mop heads would leave polish residue behind on the skirting boards, door kicker plates, and on the base of any equipment that the mop head brushed against, using a flat microfiber mop and face cloth stops this problem, if you cant source microfiber face cloths just use a standard terry microfiber cloth.