don't you hate how potions don't stack? how about we make a Potion gun! that loads like the CFoam Sprayer does and changes the color of the tip of the gun as to what potions are loaded into it. it would change colors like the painters do, if a normal potion is loaded into it then you get the bottle back and it works like a mining laser and puts the buff or de-buff on the first thing it hits, so you could load speed potions into it and shoot an ally and it would give them the speed potion affect. or you could load a Splash Potion into it in order to hit all targets in the area around the first point of contact, but you would not get the bottle back, basically just increasing the range you can "throw" a splash potion. each gun could hold 16 shots.
or you could go with injectors, which uses non-splash potions and lets you use it on either you, an ally, or enemy. this would store 16-32 uses and you could use it to inject everyone around you including players, Wolfs, Iron Golems. that way you could increase their movement speed to keep up with you, damage, or use it to heal them by putting regenerative potions or health potions into the injector.