If you pour a health bottle over your hands or while you're reloading your gun, you can press the block button (L1) to cancel the animation and still get the full benefits. This way you speed up the healing process and gun reloading with a few seconds. This can save your life and is really great to use in Madhouse mode. Keep in mind when reloading the gun, make sure you see the number is green (or changes if your ammo won't fill the gun to max, or you need to fire a round fast) before you press the Block button. This can be useful for some slower reload weapons like the Grenade Launcher, and the Shotguns.