Be carefull removing the cable at the throttle body when you pull out the spring clip it could go ping and be lost forever spread a sheet under just in case and grip really firm with stout pliers, now I have tried oil before thin and thick but the best thing is to use a spray lubricant that contains Teflon ( halfords ) Mine has lasted ages, to create a funnel I used a mastic gun nozel, one of the larger ones and cut it at exactly the right place to be a tight fit on the outer cable flange, I hang the end up with a bungee , when you squirt the oil in wiggle the cable back and forth quite a few times to draw the lube in, when you see it at the other end job done