Sure female condoms might work well for that time of the month but I think it would still be necessary to use a sponge of some sort as well.
Not only that but I think it would also be good practice to let the client know BEFORE you arrive that it is that time of the month for you and let him decide whether he still wants to see you or not.
I would assume that most men who like to perform DATY would not be too pleased to find out after you arrive.
Taking the pill continuously does work if the right dosage for you is taken, although you might find it difficult to find a doctor who is willing to perscribe contraceptives for this reason and some doctors who will, make you take the placebo every 3 months so instead of getting your period every month you will get it every 3 months.
Depo is a take your chances sort of thing. I know a few girls who had to stop taking it because the wieght gain and mood swings were just too much for them to handle, and once you get the shot you are stuck with it for at least 3 months. I know a few others who have taken it bleed slightly all the time, maybe that is why it is such a good contraceptive, if you bleed all the time, or are so bitchy or fat that you never want to have sex, you never get preggers. Sounds like fun to me, NOT
PS. I believe norplant was banned due to high incidents of complications