I don't think it was too common, but these cars did see other use than exclusively as idlers. The link shows this same car as loaded on Oct 6, 1966 (I found the date of the stock move) on the lumber mill spur shortly before 498 pulled it out.
The second photo shows 6736 in its more typical use in Durango, August 1957. It also shows the paint job a lot better and that pipe was not the only long load requiring the use of idlers. McCoy Caterpillar in the background was a long-standing landmark for the south yard in Durango.
[static.flickr.com]