As for cleaning - the PET material is very hard and not at all very porous, so you can actually clean them with hot water alone. I would not boil them or use boiling water. If your tap water is hot (too hot to hold your hand under) then that should be good enough. Fill them, shake them, rinse and repeat till you're satisfied. Soak the drip tips.
Now I will say this - if you're worried about contamination from minerals, etc in your water, then you could always boil it first and then let cool some, then use for a final rinse. I never do that myself and I ain't dead yet