Flashing Sprites

I can’t seem to get my sprites to Strobe, i would like this to strobe slowly: http://oi39.tinypic.com/9hibs1.jpg
Easily enough i got the light to strobe slowly but the sprite wouldn’t even though i set the Render FX to ‘Slow Strobe’ like on the light.
Seems like a stupid question but i’m wondering if it’s possible?

Well, in case that the Render FX wouldn’t work, you can use a logic_timer set to 5 secs to toggle the sprites on/off.

Didn’t think of that, thanks.