Most of us have a towel or tack wrag in our kit we use to wipe our hands off while loading and shooting MLers. You can use some cleaning patches to hold the patch, or edge in your fingers, so your fingers don't slip on the lube when you cut it. ALWAYS use a sharp knife -- RAZOR sharp. If you don't have one, and don't know how to sharpen a knife to a razor's edge, send me a PT and I will give you references to materials to show you how to do it. There is a difference between a SAW and a knife's edge, although commercial knife makers today don't want you to know it.
A spit patch is a piece of cloth patch that you dampen with saliva-- or spit--- from your tongue and mouth. You Don't really just " spit " on the piece of cloth to dampen it. Your tongue has a great capacity of telling when something is thorough soaked with saliva, and is now soft, and able to be stretched some. Since the purpose of dampening the patch is so that it can be more easily compressed, and fill the grooves of the barrel, using saliva on sight, rather than taking the time to lube the patching the day before a shoot often saves a man from being able to shoot a match( and maybe win it) or not.
Lube was NOT always available to long hunters, and cloth was often in short supply. But saliva is available if you are alive, and can even soften leather, if its thin enough ( rabbit, squirrel, ground hog, opossum, etc.) to use as a patching material. Cutting the patch off at the muzzle insures that the patch will be adequate in width to completely separate the lead ball from touching the bore.
Using a patch that is oversized, however, or square, or probably even triangle in shape, is not going to change how the ball flys. The edges of the patching are " Whipped back "when the ball and patch exit the muzzle, causing the edges to be frayed. If you examine recovered patches( and you should always recover and examine your patches) you will see this edge- fraying.
Using an oversized patch will just create a bigger " sail" and cause the patch to separate about as fast from the ball. The larger patches act like an air brake, and usually can be found on the ground closer to the muzzle than the smaller ones, but this can vary with wind conditions, and the choice of lube used. A patch use in a smoothbore, where the ball is not spinning when it leaves the barrel, will travel with the ball a little bit farther, than if its fired out of a rifled barrel.