A wipe down with a damp cloth is good, but probably isn't enough unless you are doing it every day or two. The Woolite solution and a white Scotch Brite pad should be more than enough.
A wipe down with a damp cloth is very good but using a maintenance cleaner specifically formualted for leather will be even better as this will get rid of any grease/body oils that are sitting on the surface.
Condiitoners are not necessary but it is always adviseable to use a protector to protect the finish on the leather. Using water based products will help to rehydrate.
If it is a permanent marker and you scrub it off you will have removed the finish on the leather which will now be left as a weaker area more prone to dirt and wear.
MCWD grease is a very different problem to this one.