Do They Make These? - Pee Blocker

My DS has been potty trained for a year now. He will be 4 in a couple of weeks. Now the fun has begun with experimenting with shooting pee in certain ways. We got him to keep the pee in the toilet when he is standing by dropping a piece of toilet paper into the toilet and he has to hit it. Otherwise his target was sometimes the back of the toilet. When he is sitting he often forgets to hold his penis down when he pees and we end up with pee under the seat and over the side and onto the floor. Short of using plastic wrap as a guard to keep the pee in the toilet, which now that I think about it may be the easiest solution, has anyone seen any type of guard like this for boys? I have seen them on toilet training seats but my son is too big for anything like that. I guess if I use plastic wrap and wrap it around the seat and let it hang inside the toilet to cover the gap between the seat and toilet just in the front it should work unless he gets too carried away and the pee shoots over the seat. Gesh, boys and pee. I remember being warned when I built a house to never install a baseboard heater next to a toilet just in case I had sons. Now I know why.