I'm sorry for posting in a zombie thread. Anyone looking for a solution for accepting 0 confirmation payments may check blockcypher api:
http://dev.blockcypher.com/reference.html#zero_confirmationsIt's not mine but I think it's worth mention here since I was also struggling looking for a simple solution for this matter.
A better way would be to push the TX to the pools themselves.
Once you have a TX sent to you on your node (or you can view it on a block explorer), you have access to the raw, signed TX. You simply copy and paste the raw TX into a form that many pools have to have a particular TX included in the pools next block.
f2pool claims that any TX pushed via it's form will be given priority regardless of fee. (it is always a good practice to only accept a 0/unconfirmed TX if it included an appropriate fee)