Libbylindy – I use mineral oil/vegoil (or wd40 sprayed on some before I hang them up – don’t keep all in sand bucket) and play sand but any sand will really work. If you have lots of tools, expect to need more buckets. Any oil really IMHO would work, but mineral oil is a much thinner, finer oil – motor oil is so thick it could really goop up your tools, especially those with a fulcrum point. I follow this guy as a gardener; click here to see the ratios to use and his commentary on it.
The BEST way to sharpen a shovel? Laughter here….is to shovel #3 gravel with it! About to do that this morning!
Hope that helps.