When faced with a big box of dirty old Lionel track, a common question is whether you can just clean it up by putting it in a dishwasher.
With a few caveats, the answer is yes, but I wouldn’t say I recommend it.
Usually when old track is too messed up to clean up by hand, it’s rusty, not just dirty. Putting it in the dishwasher will eliminate the dirt and oil, but not the rust–it’s likely to make the rust worse, if anything.
The second issue is the paint on the track ties. Sometimes Lionel used a bluing agent on the track ties rather than painting them. But if they’re painted, and the track was made before 1978, you have to assume the ties had lead paint, and you don’t want lead paint in your dishwasher. The residue won’t stay there long, but it’s unpredictable how long it will stay and it’s not worth the risk of getting it on your dishes.
When dealing with a lot of dirty and rusty track, your best bet is usually to pick out the best pieces, clean those by hand, and use the rest of it for display shelves. Clean used track usually sells for less than $1 per piece so it’s not worth putting a lot of effort into it.