That is a hot load for a .32. Recall that the comparable cartridge would be the .32-20, Not the .32-40! Use 20 grains for a more reasonable load( I have found that 17 grains of 3Fg works best in modern .32-20 casings for accuracy.
AND, you need to size that bullet close to your bore diameter- .001-.002" under bore diameter-- to get the best accuracy. Also, using a felt Over Powder wad to protect the base of the bullet, and to seal gases Behind the bullet, by filling the grooves will give you much better accuracy. If the bullet you have is made with a " driving band" that requires you to drive the bullet onto the lands to seat it, that is fine- but not nearly adequate to protect the lead bullet from gas cutting. The hot gases can still travel up the grooves, and melt the sides and base of the bullet.
Cartridge reloaders refer to the OP wads as " Base Wads", designed to protect the base of a cast bullet from being burned, or melted. With a " driving band" bullet, a "Base Wad" is going to contribute a lot to fine accuracy.
Many prefer the Ox-Yoke prelubed felt wads for this purpose. I would not expect the best performance in a MLer, UNLESS the felt wad is large enough in diameter to fill the Grooves( Groove diameter). You may have to go to a .36 caliber felt wad to get this done in your gun.
As to cleaning, Use Soap and warm- not HOT-- Water and a bore brush to get into the corners of the grooves to knock out all the carbon build-up( residue) found there.
Wonderlube DOES melt down and will dissolve prior left over wonderlube, but IT DOES NOT remove BP residue. Claims to the contrary are nonsense. Too many of these older T/C rifles have ended up in Pawn shops or at garage sales, being sold because the " Barrel is shot out"-- this because you can't see any grooves in the barrel anymore. In reality, the grooves have simply filled with carbon deposits. A good cleaning with soap and water, and a good scrubbing with a bronze bore brush is all that is needed to make those "Grooves" REAPPEAR( magic?). We have several members of this forum who make a lot of money to spend on other guns, by buying these "shot out" guns, or barrels for next to nothing, then clean them properly and sell the barrels and guns at a nice profit.
With Vasoline, you may have to flush the barrel with alcohol to get that residue Out of the barrel. Vasoline is a Petroleum based product, with a much higher burn temperature than can be produced using Black Powder. Using any Petroleum based oil or grease in your MLer results in tar-like residue not only in the grooves, but also, eventually, in the powder chamber and flash channel under the nipple.
Inexpensive, Isopropyl alcohol is good enough for this work. You don't need to use expensive modern bore solvents like Hoppes, or Shooter's Choice. They work-- don't get me wrong. They simply are not necessary to clean your MLer, unless you shoot copper jacketed bullets in it, without some kind of sabot(shoe) to protect the bore.
To "flush" the barrel, with alcohol, simply remove the nipple- to clean separately--- and then plug the hole in the bolster where the nipple is screwed into the action with a cleaning patch. Now pour alcohol down the barrel, cover the bolster with one finger or thumb, and the muzzle with your other thumb, and shake the solution back and forth in the barrel. Pour it into a toilet or sink.It will come out looking very black! I dampen a patch with alcohol and run it down and out of the barrel with my cleaning jag on my range rod. If the patch still shows lines of black streaks were the corners of the grooves correspond to the patch, I use a bore brush with another patch, also dampened with alcohol, to scrub the groove to loosen the carbon, and tars. The I pour more alcohol in the barrel and repeat the shaking again. Most of the remaining tars will be located in the powder chamber and flash channel, so stand the barrel somewhere, and let the alcohol do its job in those tight places for a few minutes. Then, pour the alcohol out.
I use a pipe cleaner run down the flash channel from the bolster, to clean out any remaining residue in that channel. You will need a chamber sized brush-- usually .22-.35 caliber, depending on the caliber of your rifle, and a cleaning patch soaked in alcohol to clean the powder chamber out. The alcohol left will evaporate.
Now, use soap and water to remove the rest of the carbon and graphite that is embedded in the pores of the steel. This residue, while not corrosive, will attract and hold moisture which Will rust the barrel.
Rinse with clean water, and dry.
Now coat the bore with a good synthetic or vegetable oil to prevent rusting, or use a good product like the B/C Sheath, if you are storing the gun for any length of time.
If you insist on using a petroleum based oil to protect the barrel from rusting, then remember to remove that oil by flushing the barrel with alcohol before you shoot it again.
I still recommend storing guns Muzzle Down, to keep oil from congealing in the smaller powder chamber, or worse, in the flash channel. Just put a rag, newspapers or paper towels under the muzzle to catch the oil that drips out.
Once a week- less often if your house is heated and air conditioned-- dust the outside of the barrel, and coat both the outside and inside with some more oil or patch lube.
I use Wonderlube for both purposes, but clean the gun before taking it out to shoot. I find that the wax seems to hold the oil on the steel surfaces, and resists minor handling without letting finger prints get a permanent fix in my finish. Any wax also works well to seal the finish/wood in the stock.