found a really helpful website

[BFG Central]

I tend to forget about this site and usually go to Youtube until that draws a blank on a subject and then a second search usually end up on the "instructables"
The home made paint ball mines were a good find on there as the spray liquid all over the person that steps on them.
Very handy after the SHTF if loaded with something nasty, smelly, sticky or something to sting the eyes. Maybe flamable.