Curious, what is the actual timer / trigger on these?
Yeah those strange ordnance grenades were scary. Not to date myself too much but I remember them going off on the field. They were crazy loud!
The vinegar / baking soda thing has been done. It actually works.. sort of. Tippmann Ordnance made them a while back but I think they gave up. I did finally try one. Undid the clip, shook it up and it slowly puffed up to about 3x the size. I threw it around agressively for about 5 minutes and it finally popped. (the directions actually said "Wait 1-2 minutes) ..lol...The spray wasn't impressive at all and the paint consistency was watered down. The only mildly impressive thing was the pop. Pretty anti-climatic for $6. Here's a pic of one if you want to guess at the percentages they were using.
Free Paintball Plans - Paintball Grenades - Special Forces Grenades
BTW ... good to see ya around blackrain... thought I'd drop in as I kind of miss the old plans forum and folks lately. I like your nade design. And I hate to admit but your paint recipe is better than mine.. *cry*