In short, no.
Items with no sales price will appear on Order dockets but they won't on the Receipts or Summaries for the customers.
Here's the long version.
All Items appear on Order dockets
$0 Mods - don't appear on Receipts or Summaries
$0 Items - don't appear on Receipts or Summaries
$0 Item with say a $5 Mod added - This does appear on receipts with both the mod and the item name and displays the price.
$5 Item with $5 removed using a mod - Neither the item or the mod appears on receipt.