What is a Secret swap?
A Secret swap can be two different things, some are organized by a person who will have you send all the seeds to his/her address and then they divide them up and send different ones back to you. This kind of swap is usually seeds only.
Other Secret swaps are organized by a person who will get all the addresses of persons wishing to participate and then send you an address. You then send that person seeds or plants. You may be partnered with the same person that you are sending to or maybe not. This kind of Secret swap is usually done for Plant swaps.