just a heads up,this stuff only works in offline with bots or hosted servers with the permit of SV_CHEATS 2
Counter-Terrorist knife - "give weapon_knife_ct"
Terrorist knife - "give weapon_knife_t"

Bayonet - "give weapon_bayonet;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Flip knife - "give weapon_knife_flip;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Gut Knife - "give weapon_knife_gut;ent_fire weapon_knife addoutput "classname
weapon_knifegg"

Karambit - "give weapon_knife_karambit;ent_fire weapon_knife addoutput "classname weapon_knifegg"

M9 Bayonet - "give weapon_knife_m9_bayonet;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Huntsman - "give weapon_knife_tactical;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Butterfly - "give weapon_knife_butterfly;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Falchion - "give weapon_knife_falchion;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Shadow Daggers - give weapon_knife_push;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Golden Knife - "give weapon_knifegg;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Bowie Knife - "give weapon_knife_survival_bowie;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Ursus - "give weapon_knife_ursus;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Navaja - "give weapon_knife_gypsy_jackknife;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Stiletto - "give weapon_knife_stiletto;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Talon - "give weapon_knife_widowmaker;ent_fire weapon_knife addoutput "classname weapon_knifegg"

Spectral Kniv - "give weapon_knife_ghost;ent_fire weapon_knife addoutput "classname weapon_knifegg"

For those who actually read the names and etc
You must type in console
1. mp_drop_knife_enable 1
2. mp_weapons_allow_zeus 0
3. copy and paste a knife command in the list above and enjoy!
Rate up

give weapon_knife_;ent_fire weapon_knife addoutput "classname weapon_knifegg

The Treasure for every long time CS:GO player :

give weapon_knife_css;ent_fire weapon_knife addoutput "classname weapon_knifegg