If its not night BDing, I tend to elevate a little whilst talking to hubby as he wanders around afterwards and then get up and do stuff, but try to hold off the toilet for at least 20 or so mins - apparently anything strong swimming will be well on its way by then, so anything coming out would be the reserves as it were and probably not as important as the forerunners. Given your situation though (as per your sig), giving them a bit of a head start can't really hurt can it?
I read a funny thing about sperm finding the egg once - someone summed it up as 'think about dropping 1 million men, blindfolded, in the middle of the Simpson Desert, spinning them around 5 times and telling them to run to Perth - that's what its like for the sperm to find the egg...' which makes me giggle. My hubby refers to sperm as "total un-co's" and imagines them trying to bang up against the kidneys or something, so again, anything we can do to help them out is probably a good thing imho (I should add, my hubby does know about the human body, I think he's just using the kidneys for comic effect lol)
But this is only really my first proper cycle (last month was a bit cavalier) and I'm not BFP yet, so perhaps I'm not the person to listen to lol.
Wish my hubby was nice and on board like yours - mine laughs at me for doing the legs thing lol