"Buy cheap canteens (teleport to spawn) on a different class(es). You can do this on all 8 classes for a total of 24 canteens per wave.
Buy crit canteens on the class you are playing for the wave. How many you buy determines how many you get when you visit spawn mid wave.
Make and press binds in the following order:

bind "mouse4" "tf_respawn_on_loadoutchanges 1; load_itempreset 2; tf_respawn_on_loadoutchanges 0
bind "mouse3" "tf_respawn_on_loadoutchanges 1; load_itempreset 1; tf_respawn_on_loadoutchanges 0"


Change itempreset 2 to whatever loadout you have that doesn't have a canteen equipped and itempreset 1 to whatever loadout you play mvm with. (0 = A, 1 = B etc...). You don't need the tf_respawn stuff if you already have that on by default, I prefer not to play with it.
My bind in the video is a little different which is why I'm only on loadout C for a split second. If I had not stopped to show you the loadout this would have been faster than going to the upgrade station to buy the canteens thus this saves you $90/canteen (after the first 1-3) and approx 2-4 seconds (might be less if tele is hugging the wrong spawn)."