I always stand to empty my pouch I don't like to sit, though I have done so (mostly in public bathrooms) I have not tried sitting backwards, that sounds weird. My husband even had a special little stool build to my specifications for use at home and I empty into a little bucket.
I will also kneel in front of toilets if its not a public restroom (like a friend's house). I prefer to stand in stalls, a lot depends on how low the toilet is. I put a bit of toilet paper in the bowl and that keeps splashing to a minimum. I don't like to empty in stalls, its confined, there's no where to put anything etc. so I consider emptying there to be my last resort and I don't irrigate there, only empty. If the bathroom is crowded I won't even rinse out my cath, just stuff it back into the ziplock and rinse in when I get home (or wherever I'm going).
As you can see, many of us do things differently and thats kinda awesome that this is so flexible! My suggestion is, as you get more comfortable, try different things until you figure out what is gonna be 'your way' 