We just tested our boys, we entered our information at OFA and paid by creditcard.
After a few days, we got two test form back home. (we had to fill out two forms on the internet for information about our boys)
A very good "step by step" information form about the testing and twee swabs (we don't speak english very good and it was easy to understand for us)
After ten minuts, both tests were done and after the drying period we send everyting back to OFA.
It cost us about 1,5 hours (including the dry period of the swab card)
I don't know how it goes with a blood test, but I think it's very easy like the cheak swab test.