Novice Hand Stamper (metal)

I'm going to try to get into hand stamping. Specifically so that I can create plant markers (that last). They are insanely pricey to buy (Etsy, etc) and I want to be able to make what I want.

I have already ordered everything that I think I will need:

Stamp set
Bench block
Rubber bench block
Stamping hammer
Polish pads
100 garden stakes
100 stainless steel dog tags
Industrial sharpie
And a handful of design stamps (for cuteness factor!)

I really have no idea how any of this will turn out or if I'll be any good at it. But it'll at least give me something fun to do. I already have an idea for a spoon that I want to do for my fiance's mother for mother's day, but had a question for those who may be more familiar with the process. I was going to use a sharpie for the darkening of the letters (originally intended it to be garden art), but I also know you can use liver of sulphur for the patina effect. However, I'm going to try and not flatten the spoon if possible and stamp it that way so that it's still usable if desired. I've seen on etsy that people sell their usable spoons with the darkened letters and say it will wear off over time. I'm worried about the safety of this? Is it no big deal since it's such small quantities? Does it matter if it's sharpie or liver of sulphur? I guess I'm just really asking if it is okay to eat off the spoon?