Deathrun Secrets

On most of the deathrun maps, there are secrets; Secrets that gives you awesome trail, hat or something else. (i.e. Iceworld, steamworks, simpsons, tropical island, helix etc.)
You get those effects when you pick up a certain nade. But why doesn’t it work in my server? It works in CS1.6, CSS even TF2 (I think) but why not Gmod? I’ve only seen secrets enabled in 1 server of all the ones I played in Gmod. I’d like to know how can I do the same? Is there a command? A lua code? Whatever, please I’d really like to know. I want to make it so effects work when I pick up the secret nade in the map.

Thanks in advance.

If you still interested, you need to make working entities like weapon_flashbang, weapon_hegrenade and weapon smoke_grenade. In fact trails parented to weapons, other items, witch you can pick up. When you picked up weapon, parented entities began moving with you.