Yea but the description is of a beam attack. More specifically the beam Piccolo used at the last martial arts finale against Goku.
Makousen @ 5:12. Sorry, thought I shared the videos with the proper time stamps.
http://youtu.be/5-aWR30JTbQ?hd=1&t=5m12s
Unnamed attack @ 2:02, I've just come to call it the Demon Wave.
http://youtu.be/J6AktNzSbpU?t=2m4s
Of course, you could argue that they are the same attack, but the charge is different. That being said, we also all know DB is NOT known for being consistent with it's attack names so who the hell knows. This seems to be an argument that can go on for some time, since some will say that the one in the first video is the Makousen and the one in the second is a different attack. Then you'll have those that say the exact opposite. Point is, Light Grenade isn't the Makousen as it (Makousen) is described as a beam attack, not a ball. As for the 'Light Grenade", I see the name "Gekiretsu Kodan" pop up quite a bit, however I'm lost on the legitimacy of the name.
At least, I think that's what this argument was about.. got lost somewhere along the way I think. . .
All this hoopla aside, I'd still like to know when Piccolo actually used the Masenko in the manga OR anime, as I must be an idiot because I can't find it anywhere.