I'm Ready For 1st Purchase Of Uncleaned... A Few Qs

I am intrigued at what I've been reading here, and being a lover of ancient history I am ready to take my plunge into the world of ancient coins.

I plan on buying a small amount of uncleaned coins. I realize I may get some coins that are not that great in quality, but I want a coin that I can hold and hand off to someone when talking about the hobby.

Anyway, I plan to buy from a reference given on this forum bay who has a good e-bay reputation, and some pretty dirty coins.

Here are my nooby questions:
(1) On these cooking shows - yes, I said "cooking shows" - they say that after a certain age olive oil turns rancid. Do you change the oil after so many days, weeks, months? what quality oil. Go with the cheap stuff, or the better the oil, the better the results?
(2) I also would assume that you don't let the coins lie on each other while soaking to get maximum exposure... or does that not matter?
(3) does temperature matter for soaking?
(4) what sort of container do you use? Is there anything to shy away from, perhaps due to reactions?

As this is my first purchase, and will be small at that, I was going to buy a brush, but want one cheap.
(5) Will a soft bristle tooth brush handle the job?

okay, these are my first questions that I did not see asked elsewhere on the forum, and these are the silly questions I have.

Thanks for the help.