When I get a new rescue in, I plug their heat pad into a thermostat and leave them completely alone for 24 hours. Unless their cage is so nasty it's growing mold or something, I don't even clean the cage yet. They just went through the stress of moving/car ride/moving some more, and 24 hours more in a dirty cage is not going to make a difference. I have a quarantine room that they stay in for at least 3 months. The next day, I will put them in a tub to hang out in while I bleach out their cage and any accessories they came with. I proactively use mite spray for the first week, but if I don't see mites after that, I stop using it. Most of my rescues come with bad shed stuck on them, so lots of times they'll be soaking in the tub while I'm cleaning the cage. Once the cage is all set up with paper towels, I'll clean up the snake. I'll only work on them for about 10 minutes or so, then I'll put them up, to help lessen stress. I use a little bit of Dawn dish soap to actually clean them by putting some in my hands and rubbing to get sudsy, then let the snake just slither through once or twice, then rinse very thoroughly.

I take the first decent sample of poo to check it for parasites, and I check another one at 3 months. No handling except to change out paper towels if they mess for 1 week, then I offer food. Even though all of my rescues have come to me on live food, I've only ever offered F/T, and I've never had one refuse more than once. I don't handle them except to clean until they've eaten for me at least 3 times.

Always do things with the QT snake last. Since you've got two separated, I would work with your first BP, then the corn, then the new BP.