I gave up trying to keep plastic from sticking to the tool, instead I just wipe it on whatever junk mail I've received recently. Mine is set to about 220°C and I don't have to clean it super frequently unless I'm adding gobs of plastic for a deeper weld. I should also mention I use a soldering station which I've found has more accuracy than any plastic welders I've tried. Downside to this is that the plastic kinda ruins the coating on the tip for actual soldering, but I get around this by just swapping to another tip.