A couple of points:-
2 vanilla pods is nowhere near enough. 30, quality, pods is more realistic and not the dried up vac-pak ones they sell in supermarkets. Buy quality on-line. you could use a quality vanilla extract and prime each bottle. The last bottle I bought cost �ã45.00 (enough for 200 pts) so it will put 22p on the price of a beer.
With the fresh vanilla pods, scrape out the seeds, put the actual pod into your boil. The seeds are too delicate to be boiled and you will loose all the flavour and aroma. Mix the seeds with 1/2 pint of boiled and cooled stock syrup (recipe for stock syrup is 1/4pt of water, 1/4 pt of sugar, boil and cool).
Put 1 tbs of this into your bottles and fill with beer.
I worked with fresh vanilla pods every day for 15 years and must of scraped thousands of them (until I found a quality exact)
Syphoning with your mouth...There are more good bacteria, than bad on your lips. if there wasnt your lips would fall off
Vanilla porter is quite a hard brew to get right. You have to balance the malts, vanilla, and the hops. Keep the hops low or you will overpower the vanilla ( no more than 20 IBU)