Haven't tried any foaming copper agents yet, however I do use a dedicated copper remover like Barnes Cr10 or Sweets 7.62 in all my guns. I have never encountered a problem with either of these agents, however I make sure to remove the product by way of dry patches, followed by a patch with isopropyl Alcohol, dry patch & then a liberally light gun oil like Sheathsoaked patch run through to protect the bore during storage.

If you ran a patch with gun oil down it after the foaming cleaner process you should be ok as well. Like BC states not the agent itself but rather a reaction to the properties thatmay cause damage over time if left unattended.