How do you make players invisible on your own server?

[Ber Rune]

I want to be able to make all players on my server invisible for an event, but the only command I know to make players invisible is r_drawothermodels 0, but that is a client side command only. So I either need to be able to force that command or have another.
Also, if you find an sm mod for this, that would work too. I could not find one that did this. The only one remotely close was making your character model smaller until it wasnt visible, which also made it not targetable/hittable. So no to that.

[Ber Rune]

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[Professor Finesser]

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[Clairin]

https://www.youtube.com/watch?v=os2uP0ikDs8

[Funz]

https://forums.alliedmods.net/showthread.php?p=665771?p=665771

[Ber Rune]

Neither worked.

[Lim]

smii7y!!