I disagree as well. Measure it and know what the mod is doing, and in many cases it's easy to improve. "Vaping well" is subjective, and if efficiency from battery to coil can be improved, I'm very interested -- and it isn't because the contacts are dirty.
Are you seriously suggesting people use
*gasoline* to clean contacts? Every item you mention is potentially flammable and should be used with caution, but the closest gasoline is coming to my vaping gear is when I'm actually pumping it. After shave lotion is in most cases full of lubricants that I wouldn't want in my mod, as well.
While I suppose it's a good idea to lock the switch (I never do), "battery firing without a load" is the same as it sitting on a table. It's not "disastrous" and doesn't reduce battery life. Are you thinking of a hard short? Because that's not good for batteries, but firing it without an atty attached has zero effect on a battery in any mod that is assembled properly. Insulation in the mod prevents a short or it'd be hard-shorting as soon as you installed a battery.
Please be careful giving advice like this. New vapers take these tips and they become gospel to some people, and then we have a guy with a gasoline-soaked rag dabbing contacts in his bedroom.