There's no need for the asphalt sealant. That's for factory use.
You're more likely to ruin the ammo by applying sealant inside the case than not using it at all.
If you want to use sealant, get the Markron. I don't use the included brush, I use a small artists brush with a pointed tip and do a quick, light pass around the primer while they're upside down in the loading block after priming. Then a quick pass around the case mouth after the ammo is finished.
Less is better than more. It is thin and will wick it's way around the bullet, like sweating (soldering) copper pipes together.
IMO, the primer sealant is as important or more important than the case mouth sealant. I had some commercial .40 ammo go bad after it spent a week in a wet plastic bag. I got caught in a downpour, spilled a box of ammo on the bench, swore a bit, scooped them into a plastic bag and threw them into my truck. Found them a week later and about half of the first ten failed to ignite. The ones that did fire, fired normally, so the powder was still dry. I threw the rest away because I didn't want to risk lodging a bullet in the bore if the primer fired, but the powder failed (squib).
Markron is basically thin fingernail polish with a little green pigment. Same as the commercial red sealant. It cleans up with acetone/lacquer thinner even after it is dried.