After looking at all the comments. Thanks , I think the most best/suitable method to deal with the PAP come knocking is.
Open the door (smile ), try to invite them in in the pretext that you do not know who are the PAP candidates. They will have no choice but to pass you the phamplet with the face of the PAP candidates. Next ask about any upgrading in your area as they always use that as a carrot. ( Look stupid and smile ). If still can delay go for it.. Untill the last part tell them you will seriously consider voting for them. ( smile ). After cooling day [ X ] opposition.
I know you all are angry. But put your anger into good use. If you slam the door or refuse to open the door. You are giving them more time to visit more units. If 1000 people delay 5 mins of their time means they wasted 5000 mins. That also means they have less units to visit and knocking on people door late in the night which make more people fed of them.
Like wise, when oppositions came. Promise them that you will vote for them and get them to visit the next unit ASAP to buy time. We can always go to the WEB page to read about their party. Unless they have real need to use the toilet or water.
"A minute waste on PAP is a minutes earn for Opposition. A minute earn for opposition is minutes waste for PAP. This is my election manifesto "