Cease n desist for a month then try again. Then be sure it's a solid wall. Prolly wouldn't hurt a brick wall... much.
I've found that if you strategically place a woman's mouth firmly in front of your wedge, it doesn't matter much wether it shoots or flows! lol!
could try teh start stop dealio too tends to help guys build up more cum, which in turn is more likely to shoot rather than just flow