Cleaning recommendations

[Super]

For cleaning corroded battery terminals I may use a couple methods depending on the severity. A small brush attachment on my Dremel Rotary Tool gets the light stuff pretty good. For a little heavier corrosion I will use the Dremel and the vinegar (like Thara mentions above) or CRC. Heavy corrosion where metal is lost is pretty much scrapped but the next one I come across I may try the replacement method that YouTuber 'Custom Trackmaster' uses.

For Lubing and Oiling, I use 2 different products pictured below. The White Lithium Grease is made for plastic gears and I have enough to last a couple life times. I try to stay away from any 'oiling' because of the mess but there are times when it is needed like when the shaft in a motor is dry and noisy. I love the pin point lubricator because you can precisely place a small drop exactly where you want .

All used trains that come to me get a bath and depending how dirty they are will dictate how much cleaning there will be. I will completely disassemble the entire train, even the motors if real dirty, and let them soak for a while in a small tub of warm water with dish soap. Rolling stock and coaches can go in whole. After a while I will then use a fingernail brush to lightly scrub the parts to get in all the nooks and crannys.
Note: any items with stickers I don't bathe but do a hand held cleaning making sure not to get the stickers wet and dry immediately with a micro fiber towelette.