This is a combination life story and hopefully helpful tips post. The tips sum up to: you should get a waterproof protector for your bed, you should always read washing instructions for your things, and baking soda with boiling water can do wonders.
So, my story starts a little over a week ago. I was lying in bed in a diaper that was already a little wet, and I was not 100% awake, but had woken up needing to pee. I was laying on my side at the time and, it being dark and me not using my head, I decided to go and ended up leaking, quite a bit. I went to sleep anyway and dealt with it in the morning, stripping the sheets and the mattress protector.
Now, my mattress protector wasn't waterproof up to this point, but it had held up under small leaks and this was my first really big wet bed. So, I ended up with a wet and somewhat smelly mattress as well.
So first, for the mattress, I tried a couple things including some types of soap and detergent in small quantities followed by washing it through with a sponge. What ended up working was to put baking soda all over it, heat some boiling water and then pour the boiling water over the stain and let it air dry. Totally got rid of the smell, left a slight stain at the edges, but that may be impossible to avoid.
Then second problem was that I didn't read my mattress protector carefully, and when I washed it, I put it in a dryer on high because I didn't get around to that load of laundry until late in the evening the day after my accident and I was rushed. The result, as I'm sure some of you can predict, is that the covering burned and the cotton got all stuck together, pretty much ruining the thing. I put the barely living remains on the bed anyway, just to have something for a couple days, though I also took a few days off from wearing any diapers at this point.
Following all that, I've ordered a terry cloth waterproof mattress protector which has just come through today. It's been great so far. It feels really soft, and it makes very little noise. You'd have to carefully spread your hands around the bed to get even the vaguest sense that there's a waterproof protector on there, and even then, I think most people would just chalk it up to the rustle of the sheets and the duvet.
So, hopefully no more troublesome leaks, and if you haven't already, I highly recommend the mattress protector because cleaning up a mattress itself is a pain and takes all day to dry.