right, a washer is about 7p from Ren, and get a filter while your there !.......you should change the filter at every oil change !......its only about a fiver, why contaminate all your new oil ?
word of advice, go get some pond liner or plastic sheet from B&Q.......the oil comes out in a straight line but thats only when the nut is fully out, while ur unscrewin it, it will go all over ur hands and ur drive and possibly up ur arm too lol