It's also ruled on very recently
here (in the general case of how to handle all Item Enhancers)
What's the point of carrying them? The only benefit I can see is to avoid Charity. If you could play them on other people's Items, then there may be a point (given your signature), but you can't. That's what
Shrinking Powder from
The Need For Steed is for, which I'm fairly sure can be carried as it is a one-shot Item, not really an Item Enhancer and most definitely can be played on others' Items.